21274920 has 64 divisors (see below), whose sum is σ = 70920000. Its totient is φ = 5673024.

The previous prime is 21274907. The next prime is 21274933. The reversal of 21274920 is 2947212.

It is an interprime number because it is at equal distance from previous prime (21274907) and next prime (21274933).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8770 + ... + 10929.

It is an arithmetic number, because the mean of its divisors is an integer number (1108125).

Almost surely, 2^21274920 is an apocalyptic number.

21274920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21274920 is an abundant number, since it is smaller than the sum of its proper divisors (49645080).

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

21274920 is a wasteful number, since it uses less digits than its factorization.

21274920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19719 (or 19709 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21274920 is about 4612.4743901728. The cubic root of 21274920 is about 277.0911437048.

The spelling of 21274920 in words is "twenty-one million, two hundred seventy-four thousand, nine hundred twenty".