400839 has 8 divisors (see below), whose sum is σ = 544752. Its totient is φ = 262080.

The previous prime is 400837. The next prime is 400849. The reversal of 400839 is 938004.

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

It is not a de Polignac number, because 400839 - 2¹ = 400837 is a prime.

400839 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1102 + ... + 1419.

It is an arithmetic number, because the mean of its divisors is an integer number (68094).

2⁴⁰⁰⁸³⁹ is an apocalyptic number.

400839 is a deficient number, since it is larger than the sum of its proper divisors (143913).

400839 is a wasteful number, since it uses less digits than its factorization.

400839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2577.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 400839 is about 633.1184723257. The cubic root of 400839 is about 73.7321090376.

The spelling of 400839 in words is "four hundred thousand, eight hundred thirty-nine".