399980957 has 2 divisors, whose sum is σ = 399980958. Its totient is φ = 399980956.

The previous prime is 399980939. The next prime is 399980993. The reversal of 399980957 is 759089993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 281367076 + 118613881 = 16774^2 + 10891^2 .

It is a cyclic number.

It is not a de Polignac number, because 399980957 - 2²⁶ = 332872093 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 399980896 and 399980905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399983957) 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, 199990478 + 199990479.

It is an arithmetic number, because the mean of its divisors is an integer number (199990479).

Almost surely, 2^399980957 is an apocalyptic number.

It is an amenable number.

399980957 is a deficient number, since it is larger than the sum of its proper divisors (1).

399980957 is an equidigital number, since it uses as much as digits as its factorization.

399980957 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5511240, while the sum is 59.

The square root of 399980957 is about 19999.5239193337. The cubic root of 399980957 is about 736.7946070406.

The spelling of 399980957 in words is "three hundred ninety-nine million, nine hundred eighty thousand, nine hundred fifty-seven".