405831 has 4 divisors (see below), whose sum is σ = 541112. Its totient is φ = 270552.

The previous prime is 405829. The next prime is 405857. The reversal of 405831 is 138504.

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

It is not a de Polignac number, because 405831 - 2¹ = 405829 is a prime.

It is a super-2 number, since 2×405831² = 329397601122, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 405798 and 405807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405871) 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, 67636 + ... + 67641.

It is an arithmetic number, because the mean of its divisors is an integer number (135278).

2⁴⁰⁵⁸³¹ is an apocalyptic number.

405831 is a deficient number, since it is larger than the sum of its proper divisors (135281).

405831 is a wasteful number, since it uses less digits than its factorization.

405831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135280.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 405831 is about 637.0486637613. The cubic root of 405831 is about 74.0369306775.

The spelling of 405831 in words is "four hundred five thousand, eight hundred thirty-one".