491407979 has 2 divisors, whose sum is σ = 491407980. Its totient is φ = 491407978.

The previous prime is 491407957. The next prime is 491407981. The reversal of 491407979 is 979704194.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 491407979 - 2¹⁶ = 491342443 is a prime.

It is a Sophie Germain prime.

Together with 491407981, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (491407079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245703989 + 245703990.

It is an arithmetic number, because the mean of its divisors is an integer number (245703990).

Almost surely, 2^491407979 is an apocalyptic number.

491407979 is a deficient number, since it is larger than the sum of its proper divisors (1).

491407979 is an equidigital number, since it uses as much as digits as its factorization.

491407979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 571536, while the sum is 50.

The square root of 491407979 is about 22167.7238118847. The cubic root of 491407979 is about 789.1279053367.

The spelling of 491407979 in words is "four hundred ninety-one million, four hundred seven thousand, nine hundred seventy-nine".