91057717209 has 16 divisors (see below), whose sum is σ = 127851292800. Its totient is φ = 57533072256.

The previous prime is 91057717199. The next prime is 91057717211. The reversal of 91057717209 is 90271775019.

It is not a de Polignac number, because 91057717209 - 2¹⁵ = 91057684441 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91057715209) 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, 6046044 + ... + 6061085.

It is an arithmetic number, because the mean of its divisors is an integer number (7990705800).

Almost surely, 2^91057717209 is an apocalyptic number.

It is an amenable number.

91057717209 is a deficient number, since it is larger than the sum of its proper divisors (36793575591).

91057717209 is a wasteful number, since it uses less digits than its factorization.

91057717209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12107264.

The product of its (nonzero) digits is 277830, while the sum is 48.

The spelling of 91057717209 in words is "ninety-one billion, fifty-seven million, seven hundred seventeen thousand, two hundred nine".