21274680 has 256 divisors, whose sum is σ = 81100800. Its totient is φ = 4354560.

The previous prime is 21274679. The next prime is 21274681. The reversal of 21274680 is 8647212.

It is an interprime number because it is at equal distance from previous prime (21274679) and next prime (21274681).

It is a super-2 number, since 2×21274680² = 905224018204800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21274681) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 494739 + ... + 494781.

It is an arithmetic number, because the mean of its divisors is an integer number (316800).

Almost surely, 2^21274680 is an apocalyptic number.

21274680 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 21274680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40550400).

21274680 is an abundant number, since it is smaller than the sum of its proper divisors (59826120).

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

21274680 is a wasteful number, since it uses less digits than its factorization.

21274680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 110 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 21274680 is about 4612.4483736948. The cubic root of 21274680 is about 277.0901017561.

The spelling of 21274680 in words is "twenty-one million, two hundred seventy-four thousand, six hundred eighty".