2221855187166 has 64 divisors (see below), whose sum is σ = 5154454103040. Its totient is φ = 708097753440.

The previous prime is 2221855187159. The next prime is 2221855187177. The reversal of 2221855187166 is 6617815581222.

2221855187166 is a `hidden beast` number, since 2 + 2 + 2 + 1 + 8 + 551 + 87 + 1 + 6 + 6 = 666.

It is a super-2 number, since 2×2221855187166² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2355751 + ... + 3161213.

It is an arithmetic number, because the mean of its divisors is an integer number (80538345360).

Almost surely, 2^{2221855187166} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2221855187166, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2577227051520).

2221855187166 is an abundant number, since it is smaller than the sum of its proper divisors (2932598915874).

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

2221855187166 is a wasteful number, since it uses less digits than its factorization.

2221855187166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 807718 (or 807712 counting only the distinct ones).

The product of its digits is 3225600, while the sum is 54.

The spelling of 2221855187166 in words is "two trillion, two hundred twenty-one billion, eight hundred fifty-five million, one hundred eighty-seven thousand, one hundred sixty-six".