491172863 has 2 divisors, whose sum is σ = 491172864. Its totient is φ = 491172862.

The previous prime is 491172859. The next prime is 491172883. The reversal of 491172863 is 368271194.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 491172863 - 2² = 491172859 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 491172863.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491172853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245586431 + 245586432.

It is an arithmetic number, because the mean of its divisors is an integer number (245586432).

Almost surely, 2^491172863 is an apocalyptic number.

491172863 is a deficient number, since it is larger than the sum of its proper divisors (1).

491172863 is an equidigital number, since it uses as much as digits as its factorization.

491172863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 41.

The square root of 491172863 is about 22162.4200618976. The cubic root of 491172863 is about 789.0020315193.

The spelling of 491172863 in words is "four hundred ninety-one million, one hundred seventy-two thousand, eight hundred sixty-three".