99991936538 has 32 divisors (see below), whose sum is σ = 170123318400. Its totient is φ = 43696345536.

The previous prime is 99991936507. The next prime is 99991936543. The reversal of 99991936538 is 83563919999.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 827195 + ... + 940337.

It is an arithmetic number, because the mean of its divisors is an integer number (5316353700).

Almost surely, 2^99991936538 is an apocalyptic number.

99991936538 is a deficient number, since it is larger than the sum of its proper divisors (70131381862).

99991936538 is a wasteful number, since it uses less digits than its factorization.

99991936538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114966.

The product of its digits is 127545840, while the sum is 71.

The spelling of 99991936538 in words is "ninety-nine billion, nine hundred ninety-one million, nine hundred thirty-six thousand, five hundred thirty-eight".