91165524987 has 18 divisors (see below), whose sum is σ = 124228809948. Its totient is φ = 59467850928.

The previous prime is 91165524917. The next prime is 91165525001. The reversal of 91165524987 is 78942556119.

It is a happy number.

It is not a de Polignac number, because 91165524987 - 2¹⁹ = 91165000699 is a prime.

It is a super-2 number, since 2×91165524987² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91165524917) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 24577689 + ... + 24581397.

Almost surely, 2^91165524987 is an apocalyptic number.

91165524987 is a deficient number, since it is larger than the sum of its proper divisors (33063284961).

91165524987 is an frugal number, since it uses more digits than its factorization.

91165524987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7515 (or 3759 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 57.

The spelling of 91165524987 in words is "ninety-one billion, one hundred sixty-five million, five hundred twenty-four thousand, nine hundred eighty-seven".