91427931 has 12 divisors (see below), whose sum is σ = 150928752. Its totient is φ = 52244496.

The previous prime is 91427911. The next prime is 91427939. The reversal of 91427931 is 13972419.

It is not a de Polignac number, because 91427931 - 2⁵ = 91427899 is a prime.

It is a super-3 number, since 3×91427931³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (91427939) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 725556 + ... + 725681.

It is an arithmetic number, because the mean of its divisors is an integer number (12577396).

Almost surely, 2^91427931 is an apocalyptic number.

91427931 is a deficient number, since it is larger than the sum of its proper divisors (59500821).

91427931 is a wasteful number, since it uses less digits than its factorization.

91427931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1451250 (or 1451247 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 91427931 is about 9561.7953858049. The cubic root of 91427931 is about 450.4981003064.

The spelling of 91427931 in words is "ninety-one million, four hundred twenty-seven thousand, nine hundred thirty-one".