20816856 has 48 divisors (see below), whose sum is σ = 59350200. Its totient is φ = 6573312.

The previous prime is 20816839. The next prime is 20816881. The reversal of 20816856 is 65861802.

It is a happy number.

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 20816856.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6241 + ... + 8976.

Almost surely, 2^20816856 is an apocalyptic number.

It is an amenable number.

20816856 is an abundant number, since it is smaller than the sum of its proper divisors (38533344).

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

20816856 is a wasteful number, since it uses less digits than its factorization.

20816856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15248 (or 15241 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 20816856 is about 4562.5492874050. The cubic root of 20816856 is about 275.0880423333.

The spelling of 20816856 in words is "twenty million, eight hundred sixteen thousand, eight hundred fifty-six".