20156646 has 16 divisors (see below), whose sum is σ = 40520304. Its totient is φ = 6684384.

The previous prime is 20156629. The next prime is 20156681. The reversal of 20156646 is 64665102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7345 + ... + 9708.

It is an arithmetic number, because the mean of its divisors is an integer number (2532519).

Almost surely, 2^20156646 is an apocalyptic number.

20156646 is an abundant number, since it is smaller than the sum of its proper divisors (20363658).

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

20156646 is a wasteful number, since it uses less digits than its factorization.

20156646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17255.

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

The square root of 20156646 is about 4489.6153510073. The cubic root of 20156646 is about 272.1485905967.

It can be divided in two parts, 20156 and 646, that added together give a palindrome (20802).

The spelling of 20156646 in words is "twenty million, one hundred fifty-six thousand, six hundred forty-six".