399220 has 12 divisors (see below), whose sum is σ = 838404. Its totient is φ = 159680.

The previous prime is 399197. The next prime is 399221. The reversal of 399220 is 22993.

It can be written as a sum of positive squares in 2 ways, for example, as 272484 + 126736 = 522^2 + 356^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399221) by changing a digit.

399220 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 3 ways as a sum of consecutive naturals, for example, 9961 + ... + 10000.

It is an arithmetic number, because the mean of its divisors is an integer number (69867).

2³⁹⁹²²⁰ is an apocalyptic number.

It is an amenable number.

399220 is an abundant number, since it is smaller than the sum of its proper divisors (439184).

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

399220 is a wasteful number, since it uses less digits than its factorization.

399220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19970 (or 19968 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 399220 is about 631.8385869825. The cubic root of 399220 is about 73.6327063995.

The spelling of 399220 in words is "three hundred ninety-nine thousand, two hundred twenty".