21512264104 has 8 divisors (see below), whose sum is σ = 40335495210. Its totient is φ = 10756132048.

The previous prime is 21512264071. The next prime is 21512264107. The reversal of 21512264104 is 40146221512.

It can be written as a sum of positive squares in only one way, i.e., 13030222500 + 8482041604 = 114150^2 + 92098^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21512264107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1344516499 + ... + 1344516514.

Almost surely, 2^21512264104 is an apocalyptic number.

It is an amenable number.

21512264104 is a deficient number, since it is larger than the sum of its proper divisors (18823231106).

21512264104 is a wasteful number, since it uses less digits than its factorization.

21512264104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2689033019 (or 2689033015 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

Adding to 21512264104 its reverse (40146221512), we get a palindrome (61658485616).

The spelling of 21512264104 in words is "twenty-one billion, five hundred twelve million, two hundred sixty-four thousand, one hundred four".