491982779 has 2 divisors, whose sum is σ = 491982780. Its totient is φ = 491982778.

The previous prime is 491982761. The next prime is 491982781. The reversal of 491982779 is 977289194.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 491982779 - 2¹⁶ = 491917243 is a prime.

Together with 491982781, 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 (491972779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245991389 + 245991390.

It is an arithmetic number, because the mean of its divisors is an integer number (245991390).

Almost surely, 2^491982779 is an apocalyptic number.

491982779 is a deficient number, since it is larger than the sum of its proper divisors (1).

491982779 is an equidigital number, since it uses as much as digits as its factorization.

491982779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2286144, while the sum is 56.

The square root of 491982779 is about 22180.6848181024. The cubic root of 491982779 is about 789.4354664666.

The spelling of 491982779 in words is "four hundred ninety-one million, nine hundred eighty-two thousand, seven hundred seventy-nine".