21251002204 has 6 divisors (see below), whose sum is σ = 37189253864. Its totient is φ = 10625501100.

The previous prime is 21251002147. The next prime is 21251002217. The reversal of 21251002204 is 40220015212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2656375272 + ... + 2656375279.

Almost surely, 2^21251002204 is an apocalyptic number.

It is an amenable number.

21251002204 is a deficient number, since it is larger than the sum of its proper divisors (15938251660).

21251002204 is a wasteful number, since it uses less digits than its factorization.

21251002204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5312750555 (or 5312750553 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

Adding to 21251002204 its reverse (40220015212), we get a palindrome (61471017416).

The spelling of 21251002204 in words is "twenty-one billion, two hundred fifty-one million, two thousand, two hundred four".