21274645 has 16 divisors (see below), whose sum is σ = 29393280. Its totient is φ = 14480064.

The previous prime is 21274639. The next prime is 21274651. The reversal of 21274645 is 54647212.

It is an interprime number because it is at equal distance from previous prime (21274639) and next prime (21274651).

It is a cyclic number.

It is not a de Polignac number, because 21274645 - 2⁹ = 21274133 is a prime.

It is a super-2 number, since 2×21274645² = 905221039752050, which contains 22 as substring.

It is a congruent number.

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, 2679 + ... + 7051.

It is an arithmetic number, because the mean of its divisors is an integer number (1837080).

Almost surely, 2^21274645 is an apocalyptic number.

It is an amenable number.

21274645 is a deficient number, since it is larger than the sum of its proper divisors (8118635).

21274645 is a wasteful number, since it uses less digits than its factorization.

21274645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4524.

The product of its digits is 13440, while the sum is 31.

The square root of 21274645 is about 4612.4445796129. Note that the first 3 decimals coincide. The cubic root of 21274645 is about 277.0899498046.

The spelling of 21274645 in words is "twenty-one million, two hundred seventy-four thousand, six hundred forty-five".