21237652 has 6 divisors (see below), whose sum is σ = 37165898. Its totient is φ = 10618824.

The previous prime is 21237637. The next prime is 21237661. The reversal of 21237652 is 25673212.

It can be written as a sum of positive squares in only one way, i.e., 20666116 + 571536 = 4546^2 + 756^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21237652.

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, 2654703 + ... + 2654710.

Almost surely, 2^21237652 is an apocalyptic number.

It is an amenable number.

21237652 is a deficient number, since it is larger than the sum of its proper divisors (15928246).

21237652 is a wasteful number, since it uses less digits than its factorization.

21237652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5309417 (or 5309415 counting only the distinct ones).

The product of its digits is 5040, while the sum is 28.

The square root of 21237652 is about 4608.4327053783. The cubic root of 21237652 is about 276.9292524818.

The spelling of 21237652 in words is "twenty-one million, two hundred thirty-seven thousand, six hundred fifty-two".