866808400 has 30 divisors (see below), whose sum is σ = 2082508142. Its totient is φ = 346723200.

The previous prime is 866808377. The next prime is 866808407. The reversal of 866808400 is 4808668.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 11128896 + 855679504 = 3336^2 + 29252^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866808407) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1083111 + ... + 1083910.

Almost surely, 2^866808400 is an apocalyptic number.

866808400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

866808400 is an abundant number, since it is smaller than the sum of its proper divisors (1215699742).

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

866808400 is a wasteful number, since it uses less digits than its factorization.

866808400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2167039 (or 2167028 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 40.

The square root of 866808400 is about 29441.6100103238. The cubic root of 866808400 is about 953.4714727476.

The spelling of 866808400 in words is "eight hundred sixty-six million, eight hundred eight thousand, four hundred".