491999539 has 2 divisors, whose sum is σ = 491999540. Its totient is φ = 491999538.

The previous prime is 491999537. The next prime is 491999561. The reversal of 491999539 is 935999194.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 491999539 - 2¹ = 491999537 is a prime.

Together with 491999537, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (491999531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245999769 + 245999770.

It is an arithmetic number, because the mean of its divisors is an integer number (245999770).

Almost surely, 2^491999539 is an apocalyptic number.

491999539 is a deficient number, since it is larger than the sum of its proper divisors (1).

491999539 is an equidigital number, since it uses as much as digits as its factorization.

491999539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3542940, while the sum is 58.

The square root of 491999539 is about 22181.0626210739. The cubic root of 491999539 is about 789.4444307290. Note that the first 4 decimals are identical.

The spelling of 491999539 in words is "four hundred ninety-one million, nine hundred ninety-nine thousand, five hundred thirty-nine".