21696408 has 48 divisors (see below), whose sum is σ = 60793200. Its totient is φ = 6982080.

The previous prime is 21696401. The next prime is 21696413. The reversal of 21696408 is 80469612.

21696408 is a `hidden beast` number, since 2 + 1 + 6 + 9 + 640 + 8 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21696401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3108 + ... + 7283.

It is an arithmetic number, because the mean of its divisors is an integer number (1266525).

Almost surely, 2^21696408 is an apocalyptic number.

It is an amenable number.

21696408 is an abundant number, since it is smaller than the sum of its proper divisors (39096792).

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

21696408 is a wasteful number, since it uses less digits than its factorization.

21696408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10432 (or 10425 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 21696408 is about 4657.9403173506. The cubic root of 21696408 is about 278.9090542594.

The spelling of 21696408 in words is "twenty-one million, six hundred ninety-six thousand, four hundred eight".