91166712091 has 16 divisors (see below), whose sum is σ = 112357100800. Its totient is φ = 72034243488.

The previous prime is 91166712059. The next prime is 91166712103. The reversal of 91166712091 is 19021766119.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 91166712091 - 2⁵ = 91166712059 is a prime.

It is a super-2 number, since 2×91166712091² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91166712041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 610581 + ... + 745078.

It is an arithmetic number, because the mean of its divisors is an integer number (7022318800).

Almost surely, 2^91166712091 is an apocalyptic number.

91166712091 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

91166712091 is a deficient number, since it is larger than the sum of its proper divisors (21190388709).

91166712091 is a wasteful number, since it uses less digits than its factorization.

91166712091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1356418.

The product of its (nonzero) digits is 40824, while the sum is 43.

The spelling of 91166712091 in words is "ninety-one billion, one hundred sixty-six million, seven hundred twelve thousand, ninety-one".