399999625 has 8 divisors (see below), whose sum is σ = 499199688. Its totient is φ = 319999600.

The previous prime is 399999617. The next prime is 399999629. The reversal of 399999625 is 526999993.

It can be written as a sum of positive squares in 4 ways, for example, as 6056521 + 393943104 = 2461^2 + 19848^2 .

It is not a de Polignac number, because 399999625 - 2³ = 399999617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399999629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1599874 + ... + 1600123.

It is an arithmetic number, because the mean of its divisors is an integer number (62399961).

Almost surely, 2^399999625 is an apocalyptic number.

It is an amenable number.

399999625 is a deficient number, since it is larger than the sum of its proper divisors (99200063).

399999625 is an equidigital number, since it uses as much as digits as its factorization.

399999625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3200012 (or 3200002 counting only the distinct ones).

The product of its digits is 10628820, while the sum is 61.

The square root of 399999625 is about 19999.9906249978. The cubic root of 399999625 is about 736.8060694760.

The spelling of 399999625 in words is "three hundred ninety-nine million, nine hundred ninety-nine thousand, six hundred twenty-five".