91397565 has 80 divisors (see below), whose sum is σ = 189666048. Its totient is φ = 41243904.

The previous prime is 91397557. The next prime is 91397591. The reversal of 91397565 is 56579319.

It is not a de Polignac number, because 91397565 - 2³ = 91397557 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 91397565.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 291849 + ... + 292161.

Almost surely, 2^91397565 is an apocalyptic number.

It is an amenable number.

91397565 is an abundant number, since it is smaller than the sum of its proper divisors (98268483).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91397565 is a wasteful number, since it uses less digits than its factorization.

91397565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440 (or 431 counting only the distinct ones).

The product of its digits is 255150, while the sum is 45.

The square root of 91397565 is about 9560.2073722279. The cubic root of 91397565 is about 450.4482200713.

The spelling of 91397565 in words is "ninety-one million, three hundred ninety-seven thousand, five hundred sixty-five".