20945856 has 56 divisors (see below), whose sum is σ = 55920640. Its totient is φ = 6918912.

The previous prime is 20945851. The next prime is 20945857. The reversal of 20945856 is 65854902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20945851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23955 + ... + 24813.

Almost surely, 2^20945856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20945856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27960320).

20945856 is an abundant number, since it is smaller than the sum of its proper divisors (34974784).

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

20945856 is a wasteful number, since it uses less digits than its factorization.

20945856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001 (or 991 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 39.

The square root of 20945856 is about 4576.6642874478. The cubic root of 20945856 is about 275.6551037404.

The spelling of 20945856 in words is "twenty million, nine hundred forty-five thousand, eight hundred fifty-six".