91157139 has 6 divisors (see below), whose sum is σ = 131671436. Its totient is φ = 60771420.

The previous prime is 91157137. The next prime is 91157141. The reversal of 91157139 is 93175119.

It is an interprime number because it is at equal distance from previous prime (91157137) and next prime (91157141).

It is not a de Polignac number, because 91157139 - 2¹ = 91157137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91157137) 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, 5064277 + ... + 5064294.

Almost surely, 2^91157139 is an apocalyptic number.

91157139 is a deficient number, since it is larger than the sum of its proper divisors (40514297).

91157139 is a wasteful number, since it uses less digits than its factorization.

91157139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10128577 (or 10128574 counting only the distinct ones).

The product of its digits is 8505, while the sum is 36.

The square root of 91157139 is about 9547.6247831594. The cubic root of 91157139 is about 450.0528974854.

The spelling of 91157139 in words is "ninety-one million, one hundred fifty-seven thousand, one hundred thirty-nine".