21274278 has 16 divisors (see below), whose sum is σ = 42885120. Its totient is φ = 7035336.

The previous prime is 21274261. The next prime is 21274283. The reversal of 21274278 is 87247212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13198 + ... + 14721.

It is an arithmetic number, because the mean of its divisors is an integer number (2680320).

Almost surely, 2^21274278 is an apocalyptic number.

21274278 is an abundant number, since it is smaller than the sum of its proper divisors (21610842).

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

21274278 is a wasteful number, since it uses less digits than its factorization.

21274278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28051.

The product of its digits is 12544, while the sum is 33.

The square root of 21274278 is about 4612.4047957654. The cubic root of 21274278 is about 277.0883564745.

The spelling of 21274278 in words is "twenty-one million, two hundred seventy-four thousand, two hundred seventy-eight".