399729025 has 12 divisors (see below), whose sum is σ = 500053932. Its totient is φ = 316951040.

The previous prime is 399728999. The next prime is 399729037. The reversal of 399729025 is 520927993.

It can be written as a sum of positive squares in 6 ways, for example, as 4355569 + 395373456 = 2087^2 + 19884^2 .

It is not a de Polignac number, because 399729025 - 2¹⁷ = 399597953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 67924 + ... + 73573.

It is an arithmetic number, because the mean of its divisors is an integer number (41671161).

Almost surely, 2^399729025 is an apocalyptic number.

It is an amenable number.

399729025 is a deficient number, since it is larger than the sum of its proper divisors (100324907).

399729025 is a wasteful number, since it uses less digits than its factorization.

399729025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141620 (or 141615 counting only the distinct ones).

The product of its (nonzero) digits is 306180, while the sum is 46.

The square root of 399729025 is about 19993.2244773073. The cubic root of 399729025 is about 736.6398820707.

The spelling of 399729025 in words is "three hundred ninety-nine million, seven hundred twenty-nine thousand, twenty-five".