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20385225 = 325272432
BaseRepresentation
bin100110111000…
…0110111001001
31102100200021100
41031300313021
520204311400
62004532013
7335162100
oct115606711
942320240
1020385225
11105637a3
1269b1009
1342b9883
1429c9037
151bca100
hex1370dc9

20385225 has 81 divisors (see below), whose sum is σ = 43484103. Its totient is φ = 9102240.

The previous prime is 20385223. The next prime is 20385247. The reversal of 20385225 is 52258302.

The square root of 20385225 is 4515.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 7338681 + 13046544 = 2709^2 + 3612^2 .

It is not a de Polignac number, because 20385225 - 21 = 20385223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20385223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 474054 + ... + 474096.

Almost surely, 220385225 is an apocalyptic number.

20385225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20385225 is the 4515-th square number.

20385225 is the 2258-th centered octagonal number.

It is an amenable number.

20385225 is an abundant number, since it is smaller than the sum of its proper divisors (23098878).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20385225 is a wasteful number, since it uses less digits than its factorization.

20385225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The cubic root of 20385225 is about 273.1734597828.

The spelling of 20385225 in words is "twenty million, three hundred eighty-five thousand, two hundred twenty-five".

Divisors: 1 3 5 7 9 15 21 25 35 43 45 49 63 75 105 129 147 175 215 225 245 301 315 387 441 525 645 735 903 1075 1225 1505 1575 1849 1935 2107 2205 2709 3225 3675 4515 5547 6321 7525 9245 9675 10535 11025 12943 13545 16641 18963 22575 27735 31605 38829 46225 52675 64715 67725 83205 90601 94815 116487 138675 158025 194145 271803 323575 416025 453005 474075 582435 815409 970725 1359015 2265025 2912175 4077045 6795075 20385225