21623398568 has 16 divisors (see below), whose sum is σ = 40594000500. Its totient is φ = 10798331776.

The previous prime is 21623398567. The next prime is 21623398639. The reversal of 21623398568 is 86589332612.

It can be written as a sum of positive squares in 2 ways, for example, as 21415980964 + 207417604 = 146342^2 + 14402^2 .

It is not an unprimeable number, because it can be changed into a prime (21623398567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1664063 + ... + 1677006.

Almost surely, 2^21623398568 is an apocalyptic number.

It is an amenable number.

21623398568 is a deficient number, since it is larger than the sum of its proper divisors (18970601932).

21623398568 is a wasteful number, since it uses less digits than its factorization.

21623398568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3341884 (or 3341880 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 53.

The spelling of 21623398568 in words is "twenty-one billion, six hundred twenty-three million, three hundred ninety-eight thousand, five hundred sixty-eight".