21274065 has 24 divisors (see below), whose sum is σ = 37051560. Its totient is φ = 11291904.

The previous prime is 21274051. The next prime is 21274067. The reversal of 21274065 is 56047212.

It can be written as a sum of positive squares in 4 ways, for example, as 5089536 + 16184529 = 2256^2 + 4023^2 .

It is not a de Polignac number, because 21274065 - 2⁴ = 21274049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21274067) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9471 + ... + 11499.

It is an arithmetic number, because the mean of its divisors is an integer number (1543815).

Almost surely, 2^21274065 is an apocalyptic number.

It is an amenable number.

21274065 is a deficient number, since it is larger than the sum of its proper divisors (15777495).

21274065 is a wasteful number, since it uses less digits than its factorization.

21274065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2273 (or 2270 counting only the distinct ones).

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

The square root of 21274065 is about 4612.3817058002. The cubic root of 21274065 is about 277.0874317269.

The spelling of 21274065 in words is "twenty-one million, two hundred seventy-four thousand, sixty-five".