91313913487 has 4 divisors (see below), whose sum is σ = 91314562680. Its totient is φ = 91313264296.

The previous prime is 91313913479. The next prime is 91313913499. The reversal of 91313913487 is 78431931319.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 91313913487 - 2³ = 91313913479 is a prime.

It is a super-2 number, since 2×91313913487² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91313913487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91313913437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15493 + ... + 427630.

It is an arithmetic number, because the mean of its divisors is an integer number (22828640670).

Almost surely, 2^91313913487 is an apocalyptic number.

91313913487 is a deficient number, since it is larger than the sum of its proper divisors (649193).

91313913487 is a wasteful number, since it uses less digits than its factorization.

91313913487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649192.

The product of its digits is 489888, while the sum is 49.

The spelling of 91313913487 in words is "ninety-one billion, three hundred thirteen million, nine hundred thirteen thousand, four hundred eighty-seven".