866534400 has 198 divisors, whose sum is σ = 3103428042. Its totient is φ = 231014400.

The previous prime is 866534381. The next prime is 866534401. The reversal of 866534400 is 4435668.

866534400 is a `hidden beast` number, since 86 + 6 + 534 + 40 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 42614784 + 823919616 = 6528^2 + 28704^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866534401) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 228520 + ... + 232280.

It is an arithmetic number, because the mean of its divisors is an integer number (15673879).

Almost surely, 2^866534400 is an apocalyptic number.

866534400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866534400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1551714021).

866534400 is an abundant number, since it is smaller than the sum of its proper divisors (2236893642).

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

866534400 is a wasteful number, since it uses less digits than its factorization.

866534400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3797 (or 3771 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 866534400 is about 29436.9563644070. The cubic root of 866534400 is about 953.3709973655.

The spelling of 866534400 in words is "eight hundred sixty-six million, five hundred thirty-four thousand, four hundred".