399973 has 4 divisors (see below), whose sum is σ = 457120. Its totient is φ = 342828.

The previous prime is 399953. The next prime is 399979. The reversal of 399973 is 379993.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 399973 - 2⁵ = 399941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28563 + ... + 28576.

It is an arithmetic number, because the mean of its divisors is an integer number (114280).

2³⁹⁹⁹⁷³ is an apocalyptic number.

It is an amenable number.

399973 is a deficient number, since it is larger than the sum of its proper divisors (57147).

399973 is an equidigital number, since it uses as much as digits as its factorization.

399973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57146.

The product of its digits is 45927, while the sum is 40.

The square root of 399973 is about 632.4341862993. The cubic root of 399973 is about 73.6789721213.

It can be divided in two parts, 39997 and 3, that added together give a square (40000 = 200²).

The spelling of 399973 in words is "three hundred ninety-nine thousand, nine hundred seventy-three".