921881718794 has 16 divisors (see below), whose sum is σ = 1430528838120. Its totient is φ = 445039277760.

The previous prime is 921881718767. The next prime is 921881718833. The reversal of 921881718794 is 497817188129.

It can be written as a sum of positive squares in 4 ways, for example, as 626068650025 + 295813068769 = 791245^2 + 543887^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 921881718794.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6882824 + ... + 7015484.

Almost surely, 2^921881718794 is an apocalyptic number.

921881718794 is a deficient number, since it is larger than the sum of its proper divisors (508647119326).

921881718794 is a wasteful number, since it uses less digits than its factorization.

921881718794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252505.

The product of its digits is 16257024, while the sum is 65.

The spelling of 921881718794 in words is "nine hundred twenty-one billion, eight hundred eighty-one million, seven hundred eighteen thousand, seven hundred ninety-four".