399789 has 32 divisors (see below), whose sum is σ = 685440. Its totient is φ = 228096.

The previous prime is 399787. The next prime is 399793. The reversal of 399789 is 987993.

It is a happy number.

It is not a de Polignac number, because 399789 - 2¹ = 399787 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399781) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5934 + ... + 6000.

It is an arithmetic number, because the mean of its divisors is an integer number (21420).

2³⁹⁹⁷⁸⁹ is an apocalyptic number.

399789 is a gapful number since it is divisible by the number (39) formed by its first and last digit.

It is an amenable number.

399789 is a deficient number, since it is larger than the sum of its proper divisors (285651).

399789 is a wasteful number, since it uses less digits than its factorization.

399789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106 (or 100 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 399789 is about 632.2886998832. The cubic root of 399789 is about 73.6676721834.

The spelling of 399789 in words is "three hundred ninety-nine thousand, seven hundred eighty-nine".