21149257317 has 32 divisors (see below), whose sum is σ = 29463834624. Its totient is φ = 13479177600.

The previous prime is 21149257289. The next prime is 21149257331. The reversal of 21149257317 is 71375294112.

It is not a de Polignac number, because 21149257317 - 2⁸ = 21149257061 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21149257117) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2684418 + ... + 2692284.

It is an arithmetic number, because the mean of its divisors is an integer number (920744832).

Almost surely, 2^21149257317 is an apocalyptic number.

It is an amenable number.

21149257317 is a deficient number, since it is larger than the sum of its proper divisors (8314577307).

21149257317 is a wasteful number, since it uses less digits than its factorization.

21149257317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8249.

The product of its digits is 105840, while the sum is 42.

The spelling of 21149257317 in words is "twenty-one billion, one hundred forty-nine million, two hundred fifty-seven thousand, three hundred seventeen".