91577971617 has 16 divisors (see below), whose sum is σ = 140215077120. Its totient is φ = 52580653200.

The previous prime is 91577971609. The next prime is 91577971633. The reversal of 91577971617 is 71617977519.

It is not a de Polignac number, because 91577971617 - 2³ = 91577971609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91577171617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73028059 + ... + 73029312.

It is an arithmetic number, because the mean of its divisors is an integer number (8763442320).

Almost surely, 2^91577971617 is an apocalyptic number.

It is an amenable number.

91577971617 is a deficient number, since it is larger than the sum of its proper divisors (48637105503).

91577971617 is a wasteful number, since it uses less digits than its factorization.

91577971617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146057404.

The product of its digits is 5834430, while the sum is 60.

The spelling of 91577971617 in words is "ninety-one billion, five hundred seventy-seven million, nine hundred seventy-one thousand, six hundred seventeen".