679625021 has 2 divisors, whose sum is σ = 679625022. Its totient is φ = 679625020.

The previous prime is 679624961. The next prime is 679625027. The reversal of 679625021 is 120526976.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 664917796 + 14707225 = 25786^2 + 3835^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-679625021 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 (679625027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339812510 + 339812511.

It is an arithmetic number, because the mean of its divisors is an integer number (339812511).

Almost surely, 2^679625021 is an apocalyptic number.

It is an amenable number.

679625021 is a deficient number, since it is larger than the sum of its proper divisors (1).

679625021 is an equidigital number, since it uses as much as digits as its factorization.

679625021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 679625021 is about 26069.6187352251. The cubic root of 679625021 is about 879.2042656137.

The spelling of 679625021 in words is "six hundred seventy-nine million, six hundred twenty-five thousand, twenty-one".