399880 has 32 divisors (see below), whose sum is σ = 970200. Its totient is φ = 147456.

The previous prime is 399871. The next prime is 399887. The reversal of 399880 is 88993.

It can be written as a sum of positive squares in 4 ways, for example, as 228484 + 171396 = 478^2 + 414^2 .

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (399887) by changing a digit.

399880 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136 + ... + 904.

2³⁹⁹⁸⁸⁰ 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 399880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (485100).

399880 is an abundant number, since it is smaller than the sum of its proper divisors (570320).

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

399880 is a wasteful number, since it uses less digits than its factorization.

399880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793 (or 789 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 399880 is about 632.3606565877. The cubic root of 399880 is about 73.6732611729.

The spelling of 399880 in words is "three hundred ninety-nine thousand, eight hundred eighty".