400866 has 16 divisors (see below), whose sum is σ = 813888. Its totient is φ = 131600.

The previous prime is 400859. The next prime is 400871. The reversal of 400866 is 668004.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45 + ... + 896.

It is an arithmetic number, because the mean of its divisors is an integer number (50868).

2⁴⁰⁰⁸⁶⁶ is an apocalyptic number.

400866 is an abundant number, since it is smaller than the sum of its proper divisors (413022).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

400866 is a wasteful number, since it uses less digits than its factorization.

400866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1017.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 400866 is about 633.1397949900. The cubic root of 400866 is about 73.7337645004.

The spelling of 400866 in words is "four hundred thousand, eight hundred sixty-six".