91166956397985 has 16 divisors (see below), whose sum is σ = 157087678716864. Its totient is φ = 44882193918912.

The previous prime is 91166956397981. The next prime is 91166956398019. The reversal of 91166956397985 is 58979365966119.

It is not a de Polignac number, because 91166956397985 - 2² = 91166956397981 is a prime.

It is a super-2 number, since 2×91166956397985² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 91166956397898 and 91166956397907.

It is not an unprimeable number, because it can be changed into a prime (91166956397981) 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, 233761426467 + ... + 233761426856.

It is an arithmetic number, because the mean of its divisors is an integer number (9817979919804).

Almost surely, 2^{91166956397985} is an apocalyptic number.

It is an amenable number.

91166956397985 is a deficient number, since it is larger than the sum of its proper divisors (65920722318879).

91166956397985 is a wasteful number, since it uses less digits than its factorization.

91166956397985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467522853344.

The product of its digits is 5952139200, while the sum is 84.

The spelling of 91166956397985 in words is "ninety-one trillion, one hundred sixty-six billion, nine hundred fifty-six million, three hundred ninety-seven thousand, nine hundred eighty-five".