21312927 has 24 divisors (see below), whose sum is σ = 33820800. Its totient is φ = 12873168.

The previous prime is 21312923. The next prime is 21312959. The reversal of 21312927 is 72921312.

It is not a de Polignac number, because 21312927 - 2² = 21312923 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21312927.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312923) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1224 + ... + 6642.

It is an arithmetic number, because the mean of its divisors is an integer number (1409200).

Almost surely, 2^21312927 is an apocalyptic number.

21312927 is a deficient number, since it is larger than the sum of its proper divisors (12507873).

21312927 is a wasteful number, since it uses less digits than its factorization.

21312927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5467 (or 5464 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 21312927 is about 4616.5925746160. The cubic root of 21312927 is about 277.2560505211.

The spelling of 21312927 in words is "twenty-one million, three hundred twelve thousand, nine hundred twenty-seven".