399669625 has 16 divisors (see below), whose sum is σ = 503742096. Its totient is φ = 316560000.

The previous prime is 399669607. The next prime is 399669631. The reversal of 399669625 is 526966993.

It can be written as a sum of positive squares in 8 ways, for example, as 39087504 + 360582121 = 6252^2 + 18989^2 .

It is not a de Polignac number, because 399669625 - 2⁷ = 399669497 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3204 + ... + 28453.

It is an arithmetic number, because the mean of its divisors is an integer number (31483881).

Almost surely, 2^399669625 is an apocalyptic number.

It is an amenable number.

399669625 is a deficient number, since it is larger than the sum of its proper divisors (104072471).

399669625 is a wasteful number, since it uses less digits than its factorization.

399669625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31773 (or 31763 counting only the distinct ones).

The product of its digits is 4723920, while the sum is 55.

The square root of 399669625 is about 19991.7389188635. The cubic root of 399669625 is about 736.6033918704.

The spelling of 399669625 in words is "three hundred ninety-nine million, six hundred sixty-nine thousand, six hundred twenty-five".