494989921 has 2 divisors, whose sum is σ = 494989922. Its totient is φ = 494989920.

The previous prime is 494989879. The next prime is 494989939. The reversal of 494989921 is 129989494.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 486643600 + 8346321 = 22060^2 + 2889^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-494989921 is a prime.

It is not a weakly prime, because it can be changed into another prime (494989021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 247494960 + 247494961.

It is an arithmetic number, because the mean of its divisors is an integer number (247494961).

Almost surely, 2^494989921 is an apocalyptic number.

It is an amenable number.

494989921 is a deficient number, since it is larger than the sum of its proper divisors (1).

494989921 is an equidigital number, since it uses as much as digits as its factorization.

494989921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1679616, while the sum is 55.

The square root of 494989921 is about 22248.3689514535. The cubic root of 494989921 is about 791.0406203185.

The spelling of 494989921 in words is "four hundred ninety-four million, nine hundred eighty-nine thousand, nine hundred twenty-one".