491517709872 has 80 divisors (see below), whose sum is σ = 1453515421440. Its totient is φ = 140204480256.

The previous prime is 491517709861. The next prime is 491517709883. The reversal of 491517709872 is 278907715194.

It is an interprime number because it is at equal distance from previous prime (491517709861) and next prime (491517709883).

It is a hoax number, since the sum of its digits (60) coincides with the sum of the digits of its distinct prime factors.

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, 987222 + ... + 1399157.

It is an arithmetic number, because the mean of its divisors is an integer number (18168942768).

Almost surely, 2^491517709872 is an apocalyptic number.

491517709872 is a gapful number since it is divisible by the number (42) formed by its first and last digit.

It is an amenable number.

491517709872 is an abundant number, since it is smaller than the sum of its proper divisors (961997711568).

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

491517709872 is a wasteful number, since it uses less digits than its factorization.

491517709872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2387010 (or 2387004 counting only the distinct ones).

The product of its (nonzero) digits is 8890560, while the sum is 60.

The spelling of 491517709872 in words is "four hundred ninety-one billion, five hundred seventeen million, seven hundred nine thousand, eight hundred seventy-two".