399620 has 48 divisors (see below), whose sum is σ = 952560. Its totient is φ = 139776.

The previous prime is 399617. The next prime is 399643. The reversal of 399620 is 26993.

399620 = T₄₉ + T₅₀ + ... + T₁₃₅.

It can be written as a sum of positive squares in 8 ways, for example, as 7744 + 391876 = 88^2 + 626^2 .

It is a super-2 number, since 2×399620² = 319392288800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 399620.

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, 7514 + ... + 7566.

It is an arithmetic number, because the mean of its divisors is an integer number (19845).

2³⁹⁹⁶²⁰ 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 399620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (476280).

399620 is an abundant number, since it is smaller than the sum of its proper divisors (552940).

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

399620 is a wasteful number, since it uses less digits than its factorization.

399620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 29.

The square root of 399620 is about 632.1550442732. The cubic root of 399620 is about 73.6572903809.

The spelling of 399620 in words is "three hundred ninety-nine thousand, six hundred twenty".