91157631 has 4 divisors (see below), whose sum is σ = 121543512. Its totient is φ = 60771752.

The previous prime is 91157629. The next prime is 91157657. The reversal of 91157631 is 13675119.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91157631 - 2¹ = 91157629 is a prime.

It is a super-2 number, since 2×91157631² = 16619427379064322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 91157592 and 91157601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91157531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15192936 + ... + 15192941.

It is an arithmetic number, because the mean of its divisors is an integer number (30385878).

Almost surely, 2^91157631 is an apocalyptic number.

91157631 is a deficient number, since it is larger than the sum of its proper divisors (30385881).

91157631 is a wasteful number, since it uses less digits than its factorization.

91157631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30385880.

The product of its digits is 5670, while the sum is 33.

The square root of 91157631 is about 9547.6505486952. The cubic root of 91157631 is about 450.0537071701.

The spelling of 91157631 in words is "ninety-one million, one hundred fifty-seven thousand, six hundred thirty-one".