91571601664 has 27 divisors (see below), whose sum is σ = 182795166813. Its totient is φ = 45783379968.

The previous prime is 91571601493. The next prime is 91571601691. The reversal of 91571601664 is 46610617519.

The square root of 91571601664 is 302608.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 88804000000 + 2767601664 = 298000^2 + 52608^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 4832272 + ... + 4851184.

Almost surely, 2^91571601664 is an apocalyptic number.

91571601664 is the 302608-th square number.

It is an amenable number.

91571601664 is a deficient number, since it is larger than the sum of its proper divisors (91223565149).

91571601664 is an frugal number, since it uses more digits than its factorization.

91571601664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37842 (or 18915 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 46.

The spelling of 91571601664 in words is "ninety-one billion, five hundred seventy-one million, six hundred one thousand, six hundred sixty-four".