400636 has 12 divisors (see below), whose sum is σ = 720328. Its totient is φ = 194832.

The previous prime is 400619. The next prime is 400643. The reversal of 400636 is 636004.

It is a happy number.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1206 + ... + 1501.

2⁴⁰⁰⁶³⁶ is an apocalyptic number.

It is an amenable number.

400636 is a deficient number, since it is larger than the sum of its proper divisors (319692).

400636 is a wasteful number, since it uses less digits than its factorization.

400636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2748 (or 2746 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 400636 is about 632.9581344765. The cubic root of 400636 is about 73.7196600281.

The spelling of 400636 in words is "four hundred thousand, six hundred thirty-six".