21051057937 has 12 divisors (see below), whose sum is σ = 26051352960. Its totient is φ = 16655781168.

The previous prime is 21051057919. The next prime is 21051058009. The reversal of 21051057937 is 73975015012.

It is not a de Polignac number, because 21051057937 - 2¹⁹ = 21050533649 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21051057937.

It is not an unprimeable number, because it can be changed into a prime (21051057037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8896137 + ... + 8898502.

It is an arithmetic number, because the mean of its divisors is an integer number (2170946080).

Almost surely, 2^21051057937 is an apocalyptic number.

It is an amenable number.

21051057937 is a deficient number, since it is larger than the sum of its proper divisors (5000295023).

21051057937 is a wasteful number, since it uses less digits than its factorization.

21051057937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17794672 (or 17794659 counting only the distinct ones).

The product of its (nonzero) digits is 66150, while the sum is 40.

The spelling of 21051057937 in words is "twenty-one billion, fifty-one million, fifty-seven thousand, nine hundred thirty-seven".