20963856 has 80 divisors (see below), whose sum is σ = 59889024. Its totient is φ = 6285312.

The previous prime is 20963851. The next prime is 20963869. The reversal of 20963856 is 65836902.

It is not an unprimeable number, because it can be changed into a prime (20963851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18210 + ... + 19326.

Almost surely, 2^20963856 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 20963856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29944512).

20963856 is an abundant number, since it is smaller than the sum of its proper divisors (38925168).

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

20963856 is a wasteful number, since it uses less digits than its factorization.

20963856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1168 (or 1162 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 39.

The square root of 20963856 is about 4578.6303628924. The cubic root of 20963856 is about 275.7340433204.

The spelling of 20963856 in words is "twenty million, nine hundred sixty-three thousand, eight hundred fifty-six".