491581893465 has 224 divisors, whose sum is σ = 1019157269760. Its totient is φ = 225488448000.

The previous prime is 491581893457. The next prime is 491581893487. The reversal of 491581893465 is 564398185194.

491581893465 is a `hidden beast` number, since 4 + 9 + 1 + 5 + 81 + 8 + 93 + 465 = 666.

It is not a de Polignac number, because 491581893465 - 2³ = 491581893457 is a prime.

It is an unprimeable number.

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 223 ways as a sum of consecutive naturals, for example, 54914740 + ... + 54923690.

It is an arithmetic number, because the mean of its divisors is an integer number (4549809240).

Almost surely, 2^491581893465 is an apocalyptic number.

491581893465 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

491581893465 is an abundant number, since it is smaller than the sum of its proper divisors (527575376295).

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

491581893465 is a wasteful number, since it uses less digits than its factorization.

491581893465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9067 (or 9052 counting only the distinct ones).

The product of its digits is 37324800, while the sum is 63.

The spelling of 491581893465 in words is "four hundred ninety-one billion, five hundred eighty-one million, eight hundred ninety-three thousand, four hundred sixty-five".