866883409920 has 1920 divisors, whose sum is σ = 3760497861120. Its totient is φ = 189191946240.

The previous prime is 866883409907. The next prime is 866883409949. The reversal of 866883409920 is 29904388668.

866883409920 is a `hidden beast` number, since 8 + 6 + 68 + 83 + 409 + 92 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 37690583029 + ... + 37690583051.

It is an arithmetic number, because the mean of its divisors is an integer number (1958592636).

Almost surely, 2^866883409920 is an apocalyptic number.

866883409920 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 866883409920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1880248930560).

866883409920 is an abundant number, since it is smaller than the sum of its proper divisors (2893614451200).

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

866883409920 is an equidigital number, since it uses as much as digits as its factorization.

866883409920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 35831808, while the sum is 63.

The spelling of 866883409920 in words is "eight hundred sixty-six billion, eight hundred eighty-three million, four hundred nine thousand, nine hundred twenty".