21374720 has 36 divisors (see below), whose sum is σ = 51202200. Its totient is φ = 8549376.

The previous prime is 21374713. The next prime is 21374723. The reversal of 21374720 is 2747312.

It is a self number, because there is not a number n which added to its sum of digits gives 21374720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21374723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7070 + ... + 9629.

Almost surely, 2^21374720 is an apocalyptic number.

21374720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21374720 is an abundant number, since it is smaller than the sum of its proper divisors (29827480).

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

21374720 is an equidigital number, since it uses as much as digits as its factorization.

21374720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16720 (or 16706 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 26.

The square root of 21374720 is about 4623.2802207956. The cubic root of 21374720 is about 277.5237433354.

The spelling of 21374720 in words is "twenty-one million, three hundred seventy-four thousand, seven hundred twenty".