91974157 has 6 divisors (see below), whose sum is σ = 101095694. Its totient is φ = 83612760.

The previous prime is 91974149. The next prime is 91974191. The reversal of 91974157 is 75147919.

It can be written as a sum of positive squares in only one way, i.e., 82555396 + 9418761 = 9086^2 + 3069^2 .

It is not a de Polignac number, because 91974157 - 2³ = 91974149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91974137) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 379938 + ... + 380179.

Almost surely, 2^91974157 is an apocalyptic number.

It is an amenable number.

91974157 is a deficient number, since it is larger than the sum of its proper divisors (9121537).

91974157 is a wasteful number, since it uses less digits than its factorization.

91974157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760139 (or 760128 counting only the distinct ones).

The product of its digits is 79380, while the sum is 43.

The square root of 91974157 is about 9590.3157925065. The cubic root of 91974157 is about 451.3934698283.

It can be divided in two parts, 919 and 74157, that added together give a square (75076 = 274²).

The spelling of 91974157 in words is "ninety-one million, nine hundred seventy-four thousand, one hundred fifty-seven".