91137785855 has 4 divisors (see below), whose sum is σ = 109365343032. Its totient is φ = 72910228680.

The previous prime is 91137785839. The next prime is 91137785897. The reversal of 91137785855 is 55858773119.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 91137785855 - 2⁴ = 91137785839 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91137785794 and 91137785803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9113778581 + ... + 9113778590.

It is an arithmetic number, because the mean of its divisors is an integer number (27341335758).

Almost surely, 2^91137785855 is an apocalyptic number.

91137785855 is a deficient number, since it is larger than the sum of its proper divisors (18227557177).

91137785855 is a wasteful number, since it uses less digits than its factorization.

91137785855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18227557176.

The product of its digits is 10584000, while the sum is 59.

The spelling of 91137785855 in words is "ninety-one billion, one hundred thirty-seven million, seven hundred eighty-five thousand, eight hundred fifty-five".