21200572156 has 12 divisors (see below), whose sum is σ = 37233035280. Its totient is φ = 10562562080.

The previous prime is 21200572147. The next prime is 21200572163. The reversal of 21200572156 is 65127500212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9429736 + ... + 9431983.

It is an arithmetic number, because the mean of its divisors is an integer number (3102752940).

Almost surely, 2^21200572156 is an apocalyptic number.

It is an amenable number.

21200572156 is a deficient number, since it is larger than the sum of its proper divisors (16032463124).

21200572156 is a wasteful number, since it uses less digits than its factorization.

21200572156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18862004 (or 18862002 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 31.

The spelling of 21200572156 in words is "twenty-one billion, two hundred million, five hundred seventy-two thousand, one hundred fifty-six".