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20720361 = 343915733
BaseRepresentation
bin100111100001…
…0101011101001
31102222200222210
41033002223221
520301022421
62020035333
7341056134
oct117025351
942880883
1020720361
1110772572
126b32b49
1343a628c
142a7521b
151c44576
hex13c2ae9

20720361 has 8 divisors (see below), whose sum is σ = 27691840. Its totient is φ = 13781232.

The previous prime is 20720347. The next prime is 20720363. The reversal of 20720361 is 16302702.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20720361 - 210 = 20719337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20720363) 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 7 ways as a sum of consecutive naturals, for example, 6550 + ... + 9183.

It is an arithmetic number, because the mean of its divisors is an integer number (3461480).

Almost surely, 220720361 is an apocalyptic number.

It is an amenable number.

20720361 is a deficient number, since it is larger than the sum of its proper divisors (6971479).

20720361 is a wasteful number, since it uses less digits than its factorization.

20720361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16175.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 20720361 is about 4551.9623240972. The cubic root of 20720361 is about 274.6623337664.

The spelling of 20720361 in words is "twenty million, seven hundred twenty thousand, three hundred sixty-one".

Divisors: 1 3 439 1317 15733 47199 6906787 20720361