491181595920 has 140 divisors (see below), whose sum is σ = 1712212756236. Its totient is φ = 130981743360.

The previous prime is 491181595909. The next prime is 491181595943. The reversal of 491181595920 is 29595181194.

491181595920 is a `hidden beast` number, since 49 + 1 + 1 + 8 + 1 + 5 + 9 + 592 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 296637086736 + 194544509184 = 544644^2 + 441072^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 4152771 + ... + 4269410.

Almost surely, 2^491181595920 is an apocalyptic number.

491181595920 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

491181595920 is an abundant number, since it is smaller than the sum of its proper divisors (1221031160316).

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

491181595920 is an equidigital number, since it uses as much as digits as its factorization.

491181595920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8422212 (or 8422191 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 54.

The spelling of 491181595920 in words is "four hundred ninety-one billion, one hundred eighty-one million, five hundred ninety-five thousand, nine hundred twenty".