400439 has 4 divisors (see below), whose sum is σ = 431256. Its totient is φ = 369624.

The previous prime is 400429. The next prime is 400441. The reversal of 400439 is 934004.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400439 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 400439.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400409) 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, 15389 + ... + 15414.

It is an arithmetic number, because the mean of its divisors is an integer number (107814).

2⁴⁰⁰⁴³⁹ is an apocalyptic number.

400439 is a deficient number, since it is larger than the sum of its proper divisors (30817).

400439 is a wasteful number, since it uses less digits than its factorization.

400439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30816.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 400439 is about 632.8024968345. The cubic root of 400439 is about 73.7075749483.

The spelling of 400439 in words is "four hundred thousand, four hundred thirty-nine".