491709693918 has 32 divisors (see below), whose sum is σ = 994125138336. Its totient is φ = 162128559488.

The previous prime is 491709693859. The next prime is 491709693947. The reversal of 491709693918 is 819396907194.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 997821 + ... + 1406792.

It is an arithmetic number, because the mean of its divisors is an integer number (31066410573).

Almost surely, 2^491709693918 is an apocalyptic number.

491709693918 is an abundant number, since it is smaller than the sum of its proper divisors (502415444418).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

491709693918 is a wasteful number, since it uses less digits than its factorization.

491709693918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2404988.

The product of its (nonzero) digits is 26453952, while the sum is 66.

The spelling of 491709693918 in words is "four hundred ninety-one billion, seven hundred nine million, six hundred ninety-three thousand, nine hundred eighteen".