399840000 has 540 divisors, whose sum is σ = 1637869464. Its totient is φ = 86016000.

The previous prime is 399839989. The next prime is 399840011. The reversal of 399840000 is 48993.

It is an interprime number because it is at equal distance from previous prime (399839989) and next prime (399840011).

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 23519992 + ... + 23520008.

Almost surely, 2^399840000 is an apocalyptic number.

399840000 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399840000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (818934732).

399840000 is an abundant number, since it is smaller than the sum of its proper divisors (1238029464).

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

399840000 is an equidigital number, since it uses as much as digits as its factorization.

399840000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70 (or 34 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 399840000 is about 19995.9995999200. Note that the first 3 decimals coincide. The cubic root of 399840000 is about 736.7080457864.

Adding to 399840000 its reverse (48993), we get a palindrome (399888993).

The spelling of 399840000 in words is "three hundred ninety-nine million, eight hundred forty thousand".