21137072 has 20 divisors (see below), whose sum is σ = 44676456. Its totient is φ = 9607680.

The previous prime is 21137057. The next prime is 21137087. The reversal of 21137072 is 27073112.

It is an interprime number because it is at equal distance from previous prime (21137057) and next prime (21137087).

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

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, 59873 + ... + 60224.

Almost surely, 2^21137072 is an apocalyptic number.

21137072 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21137072 is an abundant number, since it is smaller than the sum of its proper divisors (23539384).

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

21137072 is a wasteful number, since it uses less digits than its factorization.

21137072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120116 (or 120110 counting only the distinct ones).

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 21137072 is about 4597.5071506198. The cubic root of 21137072 is about 276.4913881474.

The spelling of 21137072 in words is "twenty-one million, one hundred thirty-seven thousand, seventy-two".