21037502313 has 6 divisors (see below), whose sum is σ = 30387503354. Its totient is φ = 14025001536.

The previous prime is 21037502309. The next prime is 21037502347. The reversal of 21037502313 is 31320573012.

It can be written as a sum of positive squares in only one way, i.e., 15486060249 + 5551442064 = 124443^2 + 74508^2 .

It is not a de Polignac number, because 21037502313 - 2² = 21037502309 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21037502113) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1168750120 + ... + 1168750137.

Almost surely, 2^21037502313 is an apocalyptic number.

It is an amenable number.

21037502313 is a deficient number, since it is larger than the sum of its proper divisors (9350001041).

21037502313 is a wasteful number, since it uses less digits than its factorization.

21037502313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2337500263 (or 2337500260 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 27.

The spelling of 21037502313 in words is "twenty-one billion, thirty-seven million, five hundred two thousand, three hundred thirteen".