91137785898 has 24 divisors (see below), whose sum is σ = 185779657728. Its totient is φ = 29806062832.

The previous prime is 91137785897. The next prime is 91137786013. The reversal of 91137785898 is 89858773119.

It is not an unprimeable number, because it can be changed into a prime (91137785897) 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, 2686890 + ... + 2720597.

It is an arithmetic number, because the mean of its divisors is an integer number (7740819072).

Almost surely, 2^91137785898 is an apocalyptic number.

91137785898 is an abundant number, since it is smaller than the sum of its proper divisors (94641871830).

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

91137785898 is a wasteful number, since it uses less digits than its factorization.

91137785898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5407598 (or 5407545 counting only the distinct ones).

The product of its digits is 30481920, while the sum is 66.

The spelling of 91137785898 in words is "ninety-one billion, one hundred thirty-seven million, seven hundred eighty-five thousand, eight hundred ninety-eight".