491965139 has 2 divisors, whose sum is σ = 491965140. Its totient is φ = 491965138.

The previous prime is 491965039. The next prime is 491965141. The reversal of 491965139 is 931569194.

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-491965139 is a prime.

Together with 491965141, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 491965093 and 491965102.

It is not a weakly prime, because it can be changed into another prime (491965169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245982569 + 245982570.

It is an arithmetic number, because the mean of its divisors is an integer number (245982570).

Almost surely, 2^491965139 is an apocalyptic number.

491965139 is a deficient number, since it is larger than the sum of its proper divisors (1).

491965139 is an equidigital number, since it uses as much as digits as its factorization.

491965139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 262440, while the sum is 47.

The square root of 491965139 is about 22180.2871712699. The cubic root of 491965139 is about 789.4260313070.

The spelling of 491965139 in words is "four hundred ninety-one million, nine hundred sixty-five thousand, one hundred thirty-nine".