491800039 has 2 divisors, whose sum is σ = 491800040. Its totient is φ = 491800038.

The previous prime is 491800019. The next prime is 491800061. The reversal of 491800039 is 930008194.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 491800039 - 2⁷ = 491799911 is a prime.

It is equal to p_25946260 and since 491800039 and 25946260 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 491799977 and 491800013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491800019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245900019 + 245900020.

It is an arithmetic number, because the mean of its divisors is an integer number (245900020).

Almost surely, 2^491800039 is an apocalyptic number.

491800039 is a deficient number, since it is larger than the sum of its proper divisors (1).

491800039 is an equidigital number, since it uses as much as digits as its factorization.

491800039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 491800039 is about 22176.5650856935. The cubic root of 491800039 is about 789.3377128403.

The spelling of 491800039 in words is "four hundred ninety-one million, eight hundred thousand, thirty-nine".