20156436 has 18 divisors (see below), whose sum is σ = 50951082. Its totient is φ = 6718800.

The previous prime is 20156431. The next prime is 20156489. The reversal of 20156436 is 63465102.

20156436 is a `hidden beast` number, since 2 + 0 + 15 + 643 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16353936 + 3802500 = 4044^2 + 1950^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20156431) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 279915 + ... + 279986.

Almost surely, 2^20156436 is an apocalyptic number.

It is an amenable number.

20156436 is an abundant number, since it is smaller than the sum of its proper divisors (30794646).

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

20156436 is a wasteful number, since it uses less digits than its factorization.

20156436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 559911 (or 559906 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 20156436 is about 4489.5919636421. The cubic root of 20156436 is about 272.1476454758.

The spelling of 20156436 in words is "twenty million, one hundred fifty-six thousand, four hundred thirty-six".