91668872 has 8 divisors (see below), whose sum is σ = 171879150. Its totient is φ = 45834432.

The previous prime is 91668851. The next prime is 91668883. The reversal of 91668872 is 27886619.

It can be written as a sum of positive squares in only one way, i.e., 91661476 + 7396 = 9574^2 + 86^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5729297 + ... + 5729312.

Almost surely, 2^91668872 is an apocalyptic number.

It is an amenable number.

91668872 is a deficient number, since it is larger than the sum of its proper divisors (80210278).

91668872 is a wasteful number, since it uses less digits than its factorization.

91668872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11458615 (or 11458611 counting only the distinct ones).

The product of its digits is 290304, while the sum is 47.

The square root of 91668872 is about 9574.3862466479. The cubic root of 91668872 is about 450.8934873337.

The spelling of 91668872 in words is "ninety-one million, six hundred sixty-eight thousand, eight hundred seventy-two".