491115557778 has 16 divisors (see below), whose sum is σ = 982755554016. Its totient is φ = 163617779520.

The previous prime is 491115557767. The next prime is 491115557809. The reversal of 491115557778 is 877755511194.

It is a happy number.

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, 21839428 + ... + 21861903.

It is an arithmetic number, because the mean of its divisors is an integer number (61422222126).

Almost surely, 2^491115557778 is an apocalyptic number.

491115557778 is an abundant number, since it is smaller than the sum of its proper divisors (491639996238).

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

491115557778 is a wasteful number, since it uses less digits than its factorization.

491115557778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43703209.

The product of its digits is 12348000, while the sum is 60.

The spelling of 491115557778 in words is "four hundred ninety-one billion, one hundred fifteen million, five hundred fifty-seven thousand, seven hundred seventy-eight".