491507839 has 2 divisors, whose sum is σ = 491507840. Its totient is φ = 491507838.

The previous prime is 491507767. The next prime is 491507843. The reversal of 491507839 is 938705194.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491507839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491507899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245753919 + 245753920.

It is an arithmetic number, because the mean of its divisors is an integer number (245753920).

Almost surely, 2^491507839 is an apocalyptic number.

491507839 is a deficient number, since it is larger than the sum of its proper divisors (1).

491507839 is an equidigital number, since it uses as much as digits as its factorization.

491507839 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 46.

The square root of 491507839 is about 22169.9760712546. The cubic root of 491507839 is about 789.1813551372.

The spelling of 491507839 in words is "four hundred ninety-one million, five hundred seven thousand, eight hundred thirty-nine".