91561475 has 24 divisors (see below), whose sum is σ = 121800240. Its totient is φ = 68065920.

The previous prime is 91561471. The next prime is 91561511. The reversal of 91561475 is 57416519.

It is not a de Polignac number, because 91561475 - 2² = 91561471 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91561471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23357 + ... + 26993.

It is an arithmetic number, because the mean of its divisors is an integer number (5075010).

Almost surely, 2^91561475 is an apocalyptic number.

91561475 is a gapful number since it is divisible by the number (95) formed by its first and last digit.

91561475 is a deficient number, since it is larger than the sum of its proper divisors (30238765).

91561475 is a wasteful number, since it uses less digits than its factorization.

91561475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3719 (or 3714 counting only the distinct ones).

The product of its digits is 37800, while the sum is 38.

The square root of 91561475 is about 9568.7760450331. The cubic root of 91561475 is about 450.7173332764.

The spelling of 91561475 in words is "ninety-one million, five hundred sixty-one thousand, four hundred seventy-five".