400013 has 4 divisors (see below), whose sum is σ = 401280. Its totient is φ = 398748.

The previous prime is 400009. The next prime is 400031. The reversal of 400013 is 310004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 400013 - 2² = 400009 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400033) 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, 278 + ... + 936.

It is an arithmetic number, because the mean of its divisors is an integer number (100320).

2⁴⁰⁰⁰¹³ is an apocalyptic number.

It is an amenable number.

400013 is a deficient number, since it is larger than the sum of its proper divisors (1267).

400013 is an equidigital number, since it uses as much as digits as its factorization.

400013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1266.

The product of its (nonzero) digits is 12, while the sum is 8.

The square root of 400013 is about 632.4658093526. The cubic root of 400013 is about 73.6814281710.

Adding to 400013 its reverse (310004), we get a palindrome (710017).

Subtracting from 400013 its reverse (310004), we obtain a palindrome (90009).

It can be divided in two parts, 40001 and 3, that added together give a palindrome (40004).

The spelling of 400013 in words is "four hundred thousand, thirteen".