400823 has 2 divisors, whose sum is σ = 400824. Its totient is φ = 400822.

The previous prime is 400759. The next prime is 400837. The reversal of 400823 is 328004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400823 - 2⁶ = 400759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200411 + 200412.

It is an arithmetic number, because the mean of its divisors is an integer number (200412).

2⁴⁰⁰⁸²³ is an apocalyptic number.

400823 is a deficient number, since it is larger than the sum of its proper divisors (1).

400823 is an equidigital number, since it uses as much as digits as its factorization.

400823 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 400823 is about 633.1058363339. The cubic root of 400823 is about 73.7311279875.

Adding to 400823 its reverse (328004), we get a palindrome (728827).

The spelling of 400823 in words is "four hundred thousand, eight hundred twenty-three".