399720 has 32 divisors (see below), whose sum is σ = 1199520. Its totient is φ = 106560.

The previous prime is 399719. The next prime is 399727. The reversal of 399720 is 27993.

399720 is nontrivially palindromic in base 11.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (399727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1546 + ... + 1785.

It is an arithmetic number, because the mean of its divisors is an integer number (37485).

2³⁹⁹⁷²⁰ is an apocalyptic number.

399720 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

399720 is an abundant number, since it is smaller than the sum of its proper divisors (799800).

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

399720 is a wasteful number, since it uses less digits than its factorization.

399720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3345 (or 3341 counting only the distinct ones).

The product of its (nonzero) digits is 3402, while the sum is 30.

The square root of 399720 is about 632.2341338460. The cubic root of 399720 is about 73.6634338128.

The spelling of 399720 in words is "three hundred ninety-nine thousand, seven hundred twenty".