399001240 has 128 divisors (see below), whose sum is σ = 1035763200. Its totient is φ = 136913920.

The previous prime is 399001223. The next prime is 399001249. The reversal of 399001240 is 42100993.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 399001199 and 399001208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399001249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 900459 + ... + 900901.

It is an arithmetic number, because the mean of its divisors is an integer number (8091900).

Almost surely, 2^399001240 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 399001240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (517881600).

399001240 is an abundant number, since it is smaller than the sum of its proper divisors (636761960).

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

399001240 is a wasteful number, since it uses less digits than its factorization.

399001240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 399001240 is about 19975.0153942369. The cubic root of 399001240 is about 736.1925447327.

The spelling of 399001240 in words is "three hundred ninety-nine million, one thousand, two hundred forty".