21379971137 has 16 divisors (see below), whose sum is σ = 25895917440. Its totient is φ = 17231470848.

The previous prime is 21379971131. The next prime is 21379971139. The reversal of 21379971137 is 73117997312.

It is a cyclic number.

It is not a de Polignac number, because 21379971137 - 2⁶ = 21379971073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21379971131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43178 + ... + 211244.

It is an arithmetic number, because the mean of its divisors is an integer number (1618494840).

Almost surely, 2^21379971137 is an apocalyptic number.

It is an amenable number.

21379971137 is a deficient number, since it is larger than the sum of its proper divisors (4515946303).

21379971137 is a wasteful number, since it uses less digits than its factorization.

21379971137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169160.

The product of its digits is 500094, while the sum is 50.

The spelling of 21379971137 in words is "twenty-one billion, three hundred seventy-nine million, nine hundred seventy-one thousand, one hundred thirty-seven".