91390972 has 6 divisors (see below), whose sum is σ = 159934208. Its totient is φ = 45695484.

The previous prime is 91390951. The next prime is 91390991. The reversal of 91390972 is 27909319.

91390972 is digitally balanced in base 9, because in such base it contains all the possibile digits an equal number of times.

91390972 is strictly pandigital in base 9.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11423868 + ... + 11423875.

Almost surely, 2^91390972 is an apocalyptic number.

It is an amenable number.

91390972 is a deficient number, since it is larger than the sum of its proper divisors (68543236).

91390972 is a wasteful number, since it uses less digits than its factorization.

91390972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22847747 (or 22847745 counting only the distinct ones).

The product of its (nonzero) digits is 30618, while the sum is 40.

The square root of 91390972 is about 9559.8625513132. The cubic root of 91390972 is about 450.4373887232.

The spelling of 91390972 in words is "ninety-one million, three hundred ninety thousand, nine hundred seventy-two".