91985408565 has 8 divisors (see below), whose sum is σ = 147176653728. Its totient is φ = 49058884560.

The previous prime is 91985408549. The next prime is 91985408633. The reversal of 91985408565 is 56580458919.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91985408565 - 2⁴ = 91985408549 is a prime.

It is a super-2 number, since 2×91985408565² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 91985408499 and 91985408508.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3066180271 + ... + 3066180300.

It is an arithmetic number, because the mean of its divisors is an integer number (18397081716).

Almost surely, 2^91985408565 is an apocalyptic number.

It is an amenable number.

91985408565 is a deficient number, since it is larger than the sum of its proper divisors (55191245163).

91985408565 is a wasteful number, since it uses less digits than its factorization.

91985408565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6132360579.

The product of its (nonzero) digits is 15552000, while the sum is 60.

The spelling of 91985408565 in words is "ninety-one billion, nine hundred eighty-five million, four hundred eight thousand, five hundred sixty-five".