121557707513 has 12 divisors (see below), whose sum is σ = 133704044544. Its totient is φ = 110431721400.

The previous prime is 121557707497. The next prime is 121557707549. The reversal of 121557707513 is 315707755121.

It is not a de Polignac number, because 121557707513 - 2⁴ = 121557707497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121557707113) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 163481 + ... + 519462.

It is an arithmetic number, because the mean of its divisors is an integer number (11142003712).

Almost surely, 2^121557707513 is an apocalyptic number.

It is an amenable number.

121557707513 is a deficient number, since it is larger than the sum of its proper divisors (12146337031).

121557707513 is a wasteful number, since it uses less digits than its factorization.

121557707513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684436 (or 684425 counting only the distinct ones).

The product of its (nonzero) digits is 257250, while the sum is 44.

The spelling of 121557707513 in words is "one hundred twenty-one billion, five hundred fifty-seven million, seven hundred seven thousand, five hundred thirteen".