391674989 has 2 divisors, whose sum is σ = 391674990. Its totient is φ = 391674988.

The previous prime is 391674977. The next prime is 391675001. The reversal of 391674989 is 989476193.

It is a balanced prime because it is at equal distance from previous prime (391674977) and next prime (391675001).

It can be written as a sum of positive squares in only one way, i.e., 386790889 + 4884100 = 19667^2 + 2210^2 .

It is a cyclic number.

It is not a de Polignac number, because 391674989 - 2⁴ = 391674973 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391674919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195837494 + 195837495.

It is an arithmetic number, because the mean of its divisors is an integer number (195837495).

Almost surely, 2^391674989 is an apocalyptic number.

It is an amenable number.

391674989 is a deficient number, since it is larger than the sum of its proper divisors (1).

391674989 is an equidigital number, since it uses as much as digits as its factorization.

391674989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2939328, while the sum is 56.

The square root of 391674989 is about 19790.7804040164. The cubic root of 391674989 is about 731.6588216899.

The spelling of 391674989 in words is "three hundred ninety-one million, six hundred seventy-four thousand, nine hundred eighty-nine".