21275156 has 24 divisors (see below), whose sum is σ = 42651840. Its totient is φ = 9096192.

The previous prime is 21275129. The next prime is 21275171. The reversal of 21275156 is 65157212.

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, 17876 + ... + 19028.

It is an arithmetic number, because the mean of its divisors is an integer number (1777160).

Almost surely, 2^21275156 is an apocalyptic number.

It is a pronic number, being equal to 4612×4613.

It is an amenable number.

21275156 is an abundant number, since it is smaller than the sum of its proper divisors (21376684).

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

21275156 is a wasteful number, since it uses less digits than its factorization.

21275156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1823 (or 1821 counting only the distinct ones).

The product of its digits is 4200, while the sum is 29.

The square root of 21275156 is about 4612.4999728997. The cubic root of 21275156 is about 277.0921682800.

The spelling of 21275156 in words is "twenty-one million, two hundred seventy-five thousand, one hundred fifty-six".