491831999 has 2 divisors, whose sum is σ = 491832000. Its totient is φ = 491831998.

The previous prime is 491831993. The next prime is 491832007. The reversal of 491831999 is 999138194.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 491831999 - 2⁴ = 491831983 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 491831999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491831993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245915999 + 245916000.

It is an arithmetic number, because the mean of its divisors is an integer number (245916000).

Almost surely, 2^491831999 is an apocalyptic number.

491831999 is a deficient number, since it is larger than the sum of its proper divisors (1).

491831999 is an equidigital number, since it uses as much as digits as its factorization.

491831999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 629856, while the sum is 53.

The square root of 491831999 is about 22177.2856544709. The cubic root of 491831999 is about 789.3548110407.

The spelling of 491831999 in words is "four hundred ninety-one million, eight hundred thirty-one thousand, nine hundred ninety-nine".