2166865384320 has 1536 divisors, whose sum is σ = 9510090670080. Its totient is φ = 442451165184.

The previous prime is 2166865384267. The next prime is 2166865384337. The reversal of 2166865384320 is 234835686612.

2166865384320 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 86 + 538 + 4 + 3 + 20 = 666.

It is a super-2 number, since 2×2166865384320² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 2862437382 + ... + 2862438138.

It is an arithmetic number, because the mean of its divisors is an integer number (6191465280).

Almost surely, 2^{2166865384320} is an apocalyptic number.

2166865384320 is a gapful number since it is divisible by the number (20) 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 2166865384320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4755045335040).

2166865384320 is an abundant number, since it is smaller than the sum of its proper divisors (7343225285760).

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

2166865384320 is a wasteful number, since it uses less digits than its factorization.

2166865384320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 972 (or 957 counting only the distinct ones).

The product of its (nonzero) digits is 9953280, while the sum is 54.

The spelling of 2166865384320 in words is "two trillion, one hundred sixty-six billion, eight hundred sixty-five million, three hundred eighty-four thousand, three hundred twenty".