91978075 has 48 divisors (see below), whose sum is σ = 141419520. Its totient is φ = 57899520.

The previous prime is 91978049. The next prime is 91978087. The reversal of 91978075 is 57087919.

It is not a de Polignac number, because 91978075 - 2⁵ = 91978043 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 127566 + ... + 128284.

It is an arithmetic number, because the mean of its divisors is an integer number (2946240).

Almost surely, 2^91978075 is an apocalyptic number.

91978075 is a deficient number, since it is larger than the sum of its proper divisors (49441445).

91978075 is a wasteful number, since it uses less digits than its factorization.

91978075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 796 (or 791 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 46.

The square root of 91978075 is about 9590.5200588915. The cubic root of 91978075 is about 451.3998793625.

The spelling of 91978075 in words is "ninety-one million, nine hundred seventy-eight thousand, seventy-five".