21249232 has 10 divisors (see below), whose sum is σ = 41170418. Its totient is φ = 10624608.

The previous prime is 21249203. The next prime is 21249253. The reversal of 21249232 is 23294212.

It can be written as a sum of positive squares in only one way, i.e., 11861136 + 9388096 = 3444^2 + 3064^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21249197 and 21249206.

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, 664023 + ... + 664054.

Almost surely, 2^21249232 is an apocalyptic number.

It is an amenable number.

21249232 is a deficient number, since it is larger than the sum of its proper divisors (19921186).

21249232 is a wasteful number, since it uses less digits than its factorization.

21249232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328085 (or 1328079 counting only the distinct ones).

The product of its digits is 1728, while the sum is 25.

The square root of 21249232 is about 4609.6889265980. The cubic root of 21249232 is about 276.9795759681.

The spelling of 21249232 in words is "twenty-one million, two hundred forty-nine thousand, two hundred thirty-two".