2166120800256 has 224 divisors, whose sum is σ = 6735850790400. Its totient is φ = 618889248768.

The previous prime is 2166120800243. The next prime is 2166120800269. The reversal of 2166120800256 is 6520080216612.

It is an interprime number because it is at equal distance from previous prime (2166120800243) and next prime (2166120800269).

It is a tau number, because it is divible by the number of its divisors (224).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8301085 + ... + 8558051.

Almost surely, 2^{2166120800256} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2166120800256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3367925395200).

2166120800256 is an abundant number, since it is smaller than the sum of its proper divisors (4569729990144).

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

2166120800256 is an frugal number, since it uses more digits than its factorization.

2166120800256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257017 (or 256979 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

The spelling of 2166120800256 in words is "two trillion, one hundred sixty-six billion, one hundred twenty million, eight hundred thousand, two hundred fifty-six".