400605 has 16 divisors (see below), whose sum is σ = 679104. Its totient is φ = 200960.

The previous prime is 400601. The next prime is 400607. The reversal of 400605 is 506004.

It is not a de Polignac number, because 400605 - 2² = 400601 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400601) 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 15 ways as a sum of consecutive naturals, for example, 531 + ... + 1040.

It is an arithmetic number, because the mean of its divisors is an integer number (42444).

2⁴⁰⁰⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

400605 is a deficient number, since it is larger than the sum of its proper divisors (278499).

400605 is a wasteful number, since it uses less digits than its factorization.

400605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1596.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 400605 is about 632.9336458113. The cubic root of 400605 is about 73.7177585777.

Adding to 400605 its reverse (506004), we get a palindrome (906609).

The spelling of 400605 in words is "four hundred thousand, six hundred five".