21298638724 has 48 divisors (see below), whose sum is σ = 41610179520. Its totient is φ = 9456819840.

The previous prime is 21298638719. The next prime is 21298638731. The reversal of 21298638724 is 42783689212.

It is a super-2 number, since 2×21298638724² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 514087 + ... + 553969.

It is an arithmetic number, because the mean of its divisors is an integer number (866878740).

Almost surely, 2^21298638724 is an apocalyptic number.

It is an amenable number.

21298638724 is a deficient number, since it is larger than the sum of its proper divisors (20311540796).

21298638724 is a wasteful number, since it uses less digits than its factorization.

21298638724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40180 (or 40178 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 52.

The spelling of 21298638724 in words is "twenty-one billion, two hundred ninety-eight million, six hundred thirty-eight thousand, seven hundred twenty-four".