399249252 has 54 divisors (see below), whose sum is σ = 1022725158. Its totient is φ = 131324544.

The previous prime is 399249247. The next prime is 399249269. The reversal of 399249252 is 252942993.

399249252 is a `hidden beast` number, since 399 + 2 + 4 + 9 + 252 = 666.

It can be written as a sum of positive squares in only one way, i.e., 341732196 + 57517056 = 18486^2 + 7584^2 .

It is a junction number, because it is equal to n+sod(n) for n = 399249198 and 399249207.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 223788 + ... + 225564.

Almost surely, 2^399249252 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399249252, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (511362579).

399249252 is an abundant number, since it is smaller than the sum of its proper divisors (623475906).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399249252 is a wasteful number, since it uses less digits than its factorization.

399249252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1945 (or 1861 counting only the distinct ones).

The product of its digits is 349920, while the sum is 45.

The square root of 399249252 is about 19981.2224851234. Note that the first 3 decimals coincide. The cubic root of 399249252 is about 736.3450478244.

The spelling of 399249252 in words is "three hundred ninety-nine million, two hundred forty-nine thousand, two hundred fifty-two".