393999 has 8 divisors (see below), whose sum is σ = 534192. Its totient is φ = 258240.

The previous prime is 393997. The next prime is 394007. The reversal of 393999 is 999393.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 393999 - 2¹ = 393997 is a prime.

393999 is a modest number, since divided by 999 gives 393 as remainder.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 393999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (393997) 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, 894 + ... + 1259.

It is an arithmetic number, because the mean of its divisors is an integer number (66774).

2³⁹³⁹⁹⁹ is an apocalyptic number.

393999 is a deficient number, since it is larger than the sum of its proper divisors (140193).

393999 is a wasteful number, since it uses less digits than its factorization.

393999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2217.

The product of its digits is 59049, while the sum is 42.

The square root of 393999 is about 627.6933964923. The cubic root of 393999 is about 73.3103072795.

It can be divided in two parts, 39 and 3999, that multiplied together give a triangular number (155961 = T₅₅₈).

The spelling of 393999 in words is "three hundred ninety-three thousand, nine hundred ninety-nine".