400811 has 4 divisors (see below), whose sum is σ = 404472. Its totient is φ = 397152.

The previous prime is 400759. The next prime is 400823. The reversal of 400811 is 118004.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 400811 - 2¹⁰ = 399787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400871) 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 3 ways as a sum of consecutive naturals, for example, 1661 + ... + 1886.

It is an arithmetic number, because the mean of its divisors is an integer number (101118).

2⁴⁰⁰⁸¹¹ is an apocalyptic number.

400811 is a deficient number, since it is larger than the sum of its proper divisors (3661).

400811 is a wasteful number, since it uses less digits than its factorization.

400811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3660.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 400811 is about 633.0963591745. The cubic root of 400811 is about 73.7303921827.

Adding to 400811 its reverse (118004), we get a palindrome (518815).

The spelling of 400811 in words is "four hundred thousand, eight hundred eleven".