869785190991 has 32 divisors (see below), whose sum is σ = 1320163031040. Its totient is φ = 565643736000.

The previous prime is 869785190977. The next prime is 869785190999. The reversal of 869785190991 is 199091587968.

It is not a de Polignac number, because 869785190991 - 2²³ = 869776802383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (869785190999) 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 31 ways as a sum of consecutive naturals, for example, 9767016 + ... + 9855666.

It is an arithmetic number, because the mean of its divisors is an integer number (41255094720).

Almost surely, 2^869785190991 is an apocalyptic number.

869785190991 is a deficient number, since it is larger than the sum of its proper divisors (450377840049).

869785190991 is a wasteful number, since it uses less digits than its factorization.

869785190991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97564 (or 97558 counting only the distinct ones).

The product of its (nonzero) digits is 88179840, while the sum is 72.

The spelling of 869785190991 in words is "eight hundred sixty-nine billion, seven hundred eighty-five million, one hundred ninety thousand, nine hundred ninety-one".