21295808 has 56 divisors (see below), whose sum is σ = 45232320. Its totient is φ = 9918720.

The previous prime is 21295801. The next prime is 21295817. The reversal of 21295808 is 80859212.

It is a super-2 number, since 2×21295808² = 907022876745728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21295801) 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, 100823 + ... + 101033.

It is an arithmetic number, because the mean of its divisors is an integer number (807720).

Almost surely, 2^21295808 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 21295808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22616160).

21295808 is an abundant number, since it is smaller than the sum of its proper divisors (23936512).

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

21295808 is a wasteful number, since it uses less digits than its factorization.

21295808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325 (or 315 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 21295808 is about 4614.7381290816. The cubic root of 21295808 is about 277.1817979687.

The spelling of 21295808 in words is "twenty-one million, two hundred ninety-five thousand, eight hundred eight".