21296920 has 32 divisors (see below), whose sum is σ = 50738400. Its totient is φ = 8017408.

The previous prime is 21296909. The next prime is 21296921. The reversal of 21296920 is 2969212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21296921) 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, 14980 + ... + 16339.

It is an arithmetic number, because the mean of its divisors is an integer number (1585575).

Almost surely, 2^21296920 is an apocalyptic number.

21296920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21296920 is an abundant number, since it is smaller than the sum of its proper divisors (29441480).

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

21296920 is a wasteful number, since it uses less digits than its factorization.

21296920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31347 (or 31343 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 21296920 is about 4614.8586110519. The cubic root of 21296920 is about 277.1866224048.

The spelling of 21296920 in words is "twenty-one million, two hundred ninety-six thousand, nine hundred twenty".