91171972 has 6 divisors (see below), whose sum is σ = 159550958. Its totient is φ = 45585984.

The previous prime is 91171967. The next prime is 91172009. The reversal of 91171972 is 27917119.

It can be written as a sum of positive squares in only one way, i.e., 85488516 + 5683456 = 9246^2 + 2384^2 .

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 as a sum of consecutive naturals, namely, 11396493 + ... + 11396500.

Almost surely, 2^91171972 is an apocalyptic number.

It is an amenable number.

91171972 is a deficient number, since it is larger than the sum of its proper divisors (68378986).

91171972 is a wasteful number, since it uses less digits than its factorization.

91171972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22792997 (or 22792995 counting only the distinct ones).

The product of its digits is 7938, while the sum is 37.

The square root of 91171972 is about 9548.4015416194. The cubic root of 91171972 is about 450.0773068831.

The spelling of 91171972 in words is "ninety-one million, one hundred seventy-one thousand, nine hundred seventy-two".