91515863391 has 16 divisors (see below), whose sum is σ = 128581651200. Its totient is φ = 57737242368.

The previous prime is 91515863333. The next prime is 91515863407. The reversal of 91515863391 is 19336851519.

It is not a de Polignac number, because 91515863391 - 2²² = 91511669087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91515863311) 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, 811171 + ... + 917076.

It is an arithmetic number, because the mean of its divisors is an integer number (8036353200).

Almost surely, 2^91515863391 is an apocalyptic number.

91515863391 is a deficient number, since it is larger than the sum of its proper divisors (37065787809).

91515863391 is a wasteful number, since it uses less digits than its factorization.

91515863391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1729198.

The product of its digits is 874800, while the sum is 51.

The spelling of 91515863391 in words is "ninety-one billion, five hundred fifteen million, eight hundred sixty-three thousand, three hundred ninety-one".