91628765185 has 4 divisors (see below), whose sum is σ = 109954518228. Its totient is φ = 73303012144.

The previous prime is 91628765177. The next prime is 91628765201. The reversal of 91628765185 is 58156782619.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13210284096 + 78418481089 = 114936^2 + 280033^2 .

It is a cyclic number.

It is not a de Polignac number, because 91628765185 - 2³ = 91628765177 is a prime.

It is a Duffinian 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, 9162876514 + ... + 9162876523.

It is an arithmetic number, because the mean of its divisors is an integer number (27488629557).

It is a Proth number, since it is equal to 10923 ⋅ 2²³ + 1 and 10923 < 2²³.

Almost surely, 2^91628765185 is an apocalyptic number.

It is an amenable number.

91628765185 is a deficient number, since it is larger than the sum of its proper divisors (18325753043).

91628765185 is a wasteful number, since it uses less digits than its factorization.

91628765185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18325753042.

The product of its digits is 7257600, while the sum is 58.

The spelling of 91628765185 in words is "ninety-one billion, six hundred twenty-eight million, seven hundred sixty-five thousand, one hundred eighty-five".