399526817 has 2 divisors, whose sum is σ = 399526818. Its totient is φ = 399526816.

The previous prime is 399526789. The next prime is 399526861. The reversal of 399526817 is 718625993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 271293841 + 128232976 = 16471^2 + 11324^2 .

It is a cyclic number.

It is not a de Polignac number, because 399526817 - 2⁶ = 399526753 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (399526117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199763408 + 199763409.

It is an arithmetic number, because the mean of its divisors is an integer number (199763409).

Almost surely, 2^399526817 is an apocalyptic number.

It is an amenable number.

399526817 is a deficient number, since it is larger than the sum of its proper divisors (1).

399526817 is an equidigital number, since it uses as much as digits as its factorization.

399526817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 816480, while the sum is 50.

The square root of 399526817 is about 19988.1669244581. The cubic root of 399526817 is about 736.5156482424.

The spelling of 399526817 in words is "three hundred ninety-nine million, five hundred twenty-six thousand, eight hundred seventeen".