21312208825 has 12 divisors (see below), whose sum is σ = 27576145728. Its totient is φ = 16308472400.

The previous prime is 21312208807. The next prime is 21312208843. The reversal of 21312208825 is 52880221312.

It is an interprime number because it is at equal distance from previous prime (21312208807) and next prime (21312208843).

It is not a de Polignac number, because 21312208825 - 2⁵ = 21312208793 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18531781 + ... + 18532930.

It is an arithmetic number, because the mean of its divisors is an integer number (2298012144).

Almost surely, 2^21312208825 is an apocalyptic number.

21312208825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21312208825 is a deficient number, since it is larger than the sum of its proper divisors (6263936903).

21312208825 is a wasteful number, since it uses less digits than its factorization.

21312208825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37064744 (or 37064739 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 34.

The spelling of 21312208825 in words is "twenty-one billion, three hundred twelve million, two hundred eight thousand, eight hundred twenty-five".