400306 has 4 divisors (see below), whose sum is σ = 600462. Its totient is φ = 200152.

The previous prime is 400297. The next prime is 400307. The reversal of 400306 is 603004.

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

It can be written as a sum of positive squares in only one way, i.e., 342225 + 58081 = 585^2 + 241^2 .

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (400307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100075 + ... + 100078.

2⁴⁰⁰³⁰⁶ is an apocalyptic number.

400306 is a deficient number, since it is larger than the sum of its proper divisors (200156).

400306 is a wasteful number, since it uses less digits than its factorization.

400306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200155.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 400306 is about 632.6974000263. The cubic root of 400306 is about 73.6994137444.

The spelling of 400306 in words is "four hundred thousand, three hundred six".