21652516 has 6 divisors (see below), whose sum is σ = 37891910. Its totient is φ = 10826256.

The previous prime is 21652513. The next prime is 21652517. The reversal of 21652516 is 61525612.

It can be written as a sum of positive squares in only one way, i.e., 18748900 + 2903616 = 4330^2 + 1704^2 .

It is not an unprimeable number, because it can be changed into a prime (21652513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2706561 + ... + 2706568.

Almost surely, 2^21652516 is an apocalyptic number.

It is an amenable number.

21652516 is a deficient number, since it is larger than the sum of its proper divisors (16239394).

21652516 is a wasteful number, since it uses less digits than its factorization.

21652516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5413133 (or 5413131 counting only the distinct ones).

The product of its digits is 3600, while the sum is 28.

The square root of 21652516 is about 4653.2264075585. The cubic root of 21652516 is about 278.7208489025.

The spelling of 21652516 in words is "twenty-one million, six hundred fifty-two thousand, five hundred sixteen".