21031368 has 16 divisors (see below), whose sum is σ = 52578480. Its totient is φ = 7010448.

The previous prime is 21031357. The next prime is 21031379. The reversal of 21031368 is 86313012.

It is an interprime number because it is at equal distance from previous prime (21031357) and next prime (21031379).

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 876307 = 21031368 / (2 + 1 + 0 + 3 + 1 + 3 + 6 + 8).

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, 438130 + ... + 438177.

It is an arithmetic number, because the mean of its divisors is an integer number (3286155).

Almost surely, 2^21031368 is an apocalyptic number.

It is an amenable number.

21031368 is an abundant number, since it is smaller than the sum of its proper divisors (31547112).

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

21031368 is a wasteful number, since it uses less digits than its factorization.

21031368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876316 (or 876312 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 21031368 is about 4585.9969472297. The cubic root of 21031368 is about 276.0297174471.

The spelling of 21031368 in words is "twenty-one million, thirty-one thousand, three hundred sixty-eight".