991173364579 has 8 divisors (see below), whose sum is σ = 1004985661680. Its totient is φ = 977367407616.

The previous prime is 991173364499. The next prime is 991173364589. The reversal of 991173364579 is 975463371199.

991173364579 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 991173364579 - 2³⁷ = 853734411107 is a prime.

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 991173364579.

It is not an unprimeable number, because it can be changed into a prime (991173364589) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1269757 + ... + 1895950.

It is an arithmetic number, because the mean of its divisors is an integer number (125623207710).

Almost surely, 2^991173364579 is an apocalyptic number.

991173364579 is a deficient number, since it is larger than the sum of its proper divisors (13812297101).

991173364579 is a wasteful number, since it uses less digits than its factorization.

991173364579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3170069.

The product of its digits is 38578680, while the sum is 64.

The spelling of 991173364579 in words is "nine hundred ninety-one billion, one hundred seventy-three million, three hundred sixty-four thousand, five hundred seventy-nine".