21274560 has 168 divisors, whose sum is σ = 74889360. Its totient is φ = 5541888.

The previous prime is 21274553. The next prime is 21274579. The reversal of 21274560 is 6547212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 238996 + ... + 239084.

It is an arithmetic number, because the mean of its divisors is an integer number (445770).

Almost surely, 2^21274560 is an apocalyptic number.

21274560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21274560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37444680).

21274560 is an abundant number, since it is smaller than the sum of its proper divisors (53614800).

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

21274560 is a wasteful number, since it uses less digits than its factorization.

21274560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 182 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 21274560 is about 4612.4353654008. The cubic root of 21274560 is about 277.0895807789.

The spelling of 21274560 in words is "twenty-one million, two hundred seventy-four thousand, five hundred sixty".