866620800 has 144 divisors (see below), whose sum is σ = 3092404380. Its totient is φ = 231091200.

The previous prime is 866620793. The next prime is 866620801. The reversal of 866620800 is 8026668.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×866620800² = 1502063221985280000, which contains 22 as substring.

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 (866620801) 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, 13755 + ... + 43845.

Almost surely, 2^866620800 is an apocalyptic number.

866620800 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 866620800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1546202190).

866620800 is an abundant number, since it is smaller than the sum of its proper divisors (2225783580).

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

866620800 is a wasteful number, since it uses less digits than its factorization.

866620800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30121 (or 30101 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 866620800 is about 29438.4238708529. The cubic root of 866620800 is about 953.4026823998.

The spelling of 866620800 in words is "eight hundred sixty-six million, six hundred twenty thousand, eight hundred".