21073808 has 20 divisors (see below), whose sum is σ = 46663680. Its totient is φ = 9031584.

The previous prime is 21073799. The next prime is 21073837. The reversal of 21073808 is 80837012.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93968 + ... + 94191.

It is an arithmetic number, because the mean of its divisors is an integer number (2333184).

Almost surely, 2^21073808 is an apocalyptic number.

21073808 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21073808 is an abundant number, since it is smaller than the sum of its proper divisors (25589872).

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

21073808 is a wasteful number, since it uses less digits than its factorization.

21073808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188174 (or 188168 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21073808 is about 4590.6217443828. The cubic root of 21073808 is about 276.2152629964.

The spelling of 21073808 in words is "twenty-one million, seventy-three thousand, eight hundred eight".