21739312 has 20 divisors (see below), whose sum is σ = 48137296. Its totient is φ = 9316800.

The previous prime is 21739309. The next prime is 21739321. The reversal of 21739312 is 21393712.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96939 + ... + 97162.

Almost surely, 2^21739312 is an apocalyptic number.

It is an amenable number.

21739312 is an abundant number, since it is smaller than the sum of its proper divisors (26397984).

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

21739312 is a wasteful number, since it uses less digits than its factorization.

21739312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194116 (or 194110 counting only the distinct ones).

The product of its digits is 2268, while the sum is 28.

The square root of 21739312 is about 4662.5435118613. The cubic root of 21739312 is about 279.0927779898.

The spelling of 21739312 in words is "twenty-one million, seven hundred thirty-nine thousand, three hundred twelve".