400705 has 4 divisors (see below), whose sum is σ = 480852. Its totient is φ = 320560.

The previous prime is 400703. The next prime is 400711. The reversal of 400705 is 507004.

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

It can be written as a sum of positive squares in 2 ways, for example, as 146689 + 254016 = 383^2 + 504^2 .

It is not a de Polignac number, because 400705 - 2¹ = 400703 is a prime.

It is a Duffinian number.

400705 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (400703) 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, 40066 + ... + 40075.

It is an arithmetic number, because the mean of its divisors is an integer number (120213).

2⁴⁰⁰⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

400705 is a deficient number, since it is larger than the sum of its proper divisors (80147).

400705 is an equidigital number, since it uses as much as digits as its factorization.

400705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80146.

The product of its (nonzero) digits is 140, while the sum is 16.

The square root of 400705 is about 633.0126381045. The cubic root of 400705 is about 73.7238919365.

Subtracting from 400705 its sum of digits (16), we obtain a square (400689 = 633²).

Adding to 400705 its reverse (507004), we get a palindrome (907709).

The spelling of 400705 in words is "four hundred thousand, seven hundred five".