91918727680 has 80 divisors (see below), whose sum is σ = 237342637224. Its totient is φ = 33939210240.

The previous prime is 91918727639. The next prime is 91918727707. The reversal of 91918727680 is 8672781919.

It can be written as a sum of positive squares in 4 ways, for example, as 30009325824 + 61909401856 = 173232^2 + 248816^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1347711 + ... + 1414270.

Almost surely, 2^91918727680 is an apocalyptic number.

It is an amenable number.

91918727680 is an abundant number, since it is smaller than the sum of its proper divisors (145423909544).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91918727680 is a wasteful number, since it uses less digits than its factorization.

91918727680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2762017 (or 2762001 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 58.

The spelling of 91918727680 in words is "ninety-one billion, nine hundred eighteen million, seven hundred twenty-seven thousand, six hundred eighty".