91601631 has 16 divisors (see below), whose sum is σ = 148043520. Its totient is φ = 55515960.

The previous prime is 91601611. The next prime is 91601669. The reversal of 91601631 is 13610619.

It is not a de Polignac number, because 91601631 - 2²¹ = 89504479 is a prime.

It is a super-2 number, since 2×91601631² = 16781717603720322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 91601595 and 91601604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91601611) 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 15 ways as a sum of consecutive naturals, for example, 153915 + ... + 154508.

It is an arithmetic number, because the mean of its divisors is an integer number (9252720).

Almost surely, 2^91601631 is an apocalyptic number.

91601631 is a deficient number, since it is larger than the sum of its proper divisors (56441889).

91601631 is a wasteful number, since it uses less digits than its factorization.

91601631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308443 (or 308437 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 91601631 is about 9570.8740980122. The cubic root of 91601631 is about 450.7832138227.

The spelling of 91601631 in words is "ninety-one million, six hundred one thousand, six hundred thirty-one".