20636856 has 40 divisors (see below), whose sum is σ = 57804120. Its totient is φ = 6878736.

The previous prime is 20636813. The next prime is 20636867. The reversal of 20636856 is 65863602.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20636856.

It is a congruent number.

It is an unprimeable number.

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 9 ways as a sum of consecutive naturals, for example, 15276 + ... + 16571.

It is an arithmetic number, because the mean of its divisors is an integer number (1445103).

Almost surely, 2^20636856 is an apocalyptic number.

It is an amenable number.

20636856 is an abundant number, since it is smaller than the sum of its proper divisors (37167264).

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

20636856 is a wasteful number, since it uses less digits than its factorization.

20636856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31865 (or 31852 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 20636856 is about 4542.7806462562. The cubic root of 20636856 is about 274.2928653270.

The spelling of 20636856 in words is "twenty million, six hundred thirty-six thousand, eight hundred fifty-six".