21275636 has 24 divisors (see below), whose sum is σ = 40098240. Its totient is φ = 9840512.

The previous prime is 21275623. The next prime is 21275651. The reversal of 21275636 is 63657212.

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, 1361 + ... + 6663.

It is an arithmetic number, because the mean of its divisors is an integer number (1670760).

Almost surely, 2^21275636 is an apocalyptic number.

It is an amenable number.

21275636 is a deficient number, since it is larger than the sum of its proper divisors (18822604).

21275636 is a wasteful number, since it uses less digits than its factorization.

21275636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5383 (or 5381 counting only the distinct ones).

The product of its digits is 15120, while the sum is 32.

The square root of 21275636 is about 4612.5520051269. The cubic root of 21275636 is about 277.0942521385.

The spelling of 21275636 in words is "twenty-one million, two hundred seventy-five thousand, six hundred thirty-six".