21255632 has 10 divisors (see below), whose sum is σ = 41182818. Its totient is φ = 10627808.

The previous prime is 21255613. The next prime is 21255653. The reversal of 21255632 is 23655212.

It can be written as a sum of positive squares in only one way, i.e., 19678096 + 1577536 = 4436^2 + 1256^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 664223 + ... + 664254.

Almost surely, 2^21255632 is an apocalyptic number.

It is an amenable number.

21255632 is a deficient number, since it is larger than the sum of its proper divisors (19927186).

21255632 is a wasteful number, since it uses less digits than its factorization.

21255632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328485 (or 1328479 counting only the distinct ones).

The product of its digits is 3600, while the sum is 26.

The square root of 21255632 is about 4610.3830643451. The cubic root of 21255632 is about 277.0073807588.

The spelling of 21255632 in words is "twenty-one million, two hundred fifty-five thousand, six hundred thirty-two".