494689991 has 2 divisors, whose sum is σ = 494689992. Its totient is φ = 494689990.

The previous prime is 494689981. The next prime is 494690039. The reversal of 494689991 is 199986494.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-494689991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 494689991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (494689901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 247344995 + 247344996.

It is an arithmetic number, because the mean of its divisors is an integer number (247344996).

Almost surely, 2^494689991 is an apocalyptic number.

494689991 is a deficient number, since it is larger than the sum of its proper divisors (1).

494689991 is an equidigital number, since it uses as much as digits as its factorization.

494689991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5038848, while the sum is 59.

The square root of 494689991 is about 22241.6274359589. The cubic root of 494689991 is about 790.8808158863.

The spelling of 494689991 in words is "four hundred ninety-four million, six hundred eighty-nine thousand, nine hundred ninety-one".