400039 has 4 divisors (see below), whose sum is σ = 417456. Its totient is φ = 382624.

The previous prime is 400033. The next prime is 400051. The reversal of 400039 is 930004.

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

It is a cyclic number.

It is not a de Polignac number, because 400039 - 2³ = 400031 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 399995 and 400031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400031) 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, 8674 + ... + 8719.

It is an arithmetic number, because the mean of its divisors is an integer number (104364).

2⁴⁰⁰⁰³⁹ is an apocalyptic number.

400039 is a deficient number, since it is larger than the sum of its proper divisors (17417).

400039 is a wasteful number, since it uses less digits than its factorization.

400039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17416.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 400039 is about 632.4863634894. The cubic root of 400039 is about 73.6830245155.

The spelling of 400039 in words is "four hundred thousand, thirty-nine".