399452440 has 64 divisors (see below), whose sum is σ = 921715200. Its totient is φ = 155755392.

The previous prime is 399452419. The next prime is 399452491. The reversal of 399452440 is 44254993.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 399452393 and 399452402.

It is a congruent 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, 261519 + ... + 263041.

It is an arithmetic number, because the mean of its divisors is an integer number (14401800).

Almost surely, 2^399452440 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 399452440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (460857600).

399452440 is an abundant number, since it is smaller than the sum of its proper divisors (522262760).

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

399452440 is a wasteful number, since it uses less digits than its factorization.

399452440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1696 (or 1692 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 399452440 is about 19986.3063120728. The cubic root of 399452440 is about 736.4699414865.

The spelling of 399452440 in words is "three hundred ninety-nine million, four hundred fifty-two thousand, four hundred forty".