21507652 has 24 divisors (see below), whose sum is σ = 40068000. Its totient is φ = 10066560.

The previous prime is 21507649. The next prime is 21507653. The reversal of 21507652 is 25670512.

It is a self number, because there is not a number n which added to its sum of digits gives 21507652.

It is not an unprimeable number, because it can be changed into a prime (21507653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13599 + ... + 15097.

It is an arithmetic number, because the mean of its divisors is an integer number (1669500).

Almost surely, 2^21507652 is an apocalyptic number.

It is an amenable number.

21507652 is a deficient number, since it is larger than the sum of its proper divisors (18560348).

21507652 is a wasteful number, since it uses less digits than its factorization.

21507652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1731 (or 1729 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 21507652 is about 4637.6343107235. The cubic root of 21507652 is about 278.0978728245.

The spelling of 21507652 in words is "twenty-one million, five hundred seven thousand, six hundred fifty-two".