20646156 has 12 divisors (see below), whose sum is σ = 48174392. Its totient is φ = 6882048.

The previous prime is 20646151. The next prime is 20646163. The reversal of 20646156 is 65164602.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (20646151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 860245 + ... + 860268.

Almost surely, 2^20646156 is an apocalyptic number.

It is an amenable number.

20646156 is an abundant number, since it is smaller than the sum of its proper divisors (27528236).

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

20646156 is a wasteful number, since it uses less digits than its factorization.

20646156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1720520 (or 1720518 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 20646156 is about 4543.8041331026. The cubic root of 20646156 is about 274.3340625027.

It can be divided in two parts, 20646 and 156, that added together give a palindrome (20802).

The spelling of 20646156 in words is "twenty million, six hundred forty-six thousand, one hundred fifty-six".