399423 has 8 divisors (see below), whose sum is σ = 535936.
Its totient is φ = 264600.
The previous prime is 399409. The next prime is 399433. The reversal of 399423 is 324993.
It is a Cunningham number, because it is equal to 6322-1.
It is a sphenic number, since it is the product of 3 distinct primes.
It is not a de Polignac number, because 399423 - 25 = 399391 is a prime.
It is a D-number.
It is a Duffinian number.
399423 is a lucky number.
It is a zygodrome in base 2.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (399403) 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, 318 + ... + 948.
It is an arithmetic number, because the mean of its divisors is an integer number (66992).
2399423 is an apocalyptic number.
399423 is a deficient number, since it is larger than the sum of its proper divisors (136513).
399423 is a wasteful number, since it uses less digits than its factorization.
399423 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 845.
The product of its digits is 5832, while the sum is 30.
The square root of 399423 is about 631.9992088603.
Note that the first 3 decimals coincide.
The cubic root of 399423 is about 73.6451848212.
The spelling of 399423 in words is "three hundred ninety-nine thousand, four hundred twenty-three".