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20408 = 232551
BaseRepresentation
bin100111110111000
31000222212
410332320
51123113
6234252
7113333
oct47670
930885
1020408
1114373
12b988
13939b
14761a
1560a8
hex4fb8

20408 has 8 divisors (see below), whose sum is σ = 38280. Its totient is φ = 10200.

The previous prime is 20407. The next prime is 20411. The reversal of 20408 is 80402.

It is a tau number, because it is divible by the number of its divisors (8).

It is a plaindrome in base 7.

It is a nialpdrome in base 12.

It is a zygodrome in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 20392 and 20401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1268 + ... + 1283.

It is an arithmetic number, because the mean of its divisors is an integer number (4785).

220408 is an apocalyptic number.

It is an amenable number.

20408 is a deficient number, since it is larger than the sum of its proper divisors (17872).

20408 is a wasteful number, since it uses less digits than its factorization.

20408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2557 (or 2553 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 20408 is about 142.8565714274. The cubic root of 20408 is about 27.3275154516.

It can be divided in two parts, 2040 and 8, that added together give a 11-th power (2048 = 211).

The spelling of 20408 in words is "twenty thousand, four hundred eight".

Divisors: 1 2 4 8 2551 5102 10204 20408