491039999 has 2 divisors, whose sum is σ = 491040000. Its totient is φ = 491039998.

The previous prime is 491039981. The next prime is 491040001. The reversal of 491039999 is 999930194.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 491039999 - 2¹² = 491035903 is a prime.

It is a super-2 number, since 2×491039999² = 482240561235840002, which contains 22 as substring.

Together with 491040001, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 491039999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491039909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245519999 + 245520000.

It is an arithmetic number, because the mean of its divisors is an integer number (245520000).

Almost surely, 2^491039999 is an apocalyptic number.

491039999 is a deficient number, since it is larger than the sum of its proper divisors (1).

491039999 is an equidigital number, since it uses as much as digits as its factorization.

491039999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 708588, while the sum is 53.

The square root of 491039999 is about 22159.4223525795. The cubic root of 491039999 is about 788.9308824884.

The spelling of 491039999 in words is "four hundred ninety-one million, thirty-nine thousand, nine hundred ninety-nine".