2166221655212 has 12 divisors (see below), whose sum is σ = 3791369456616. Its totient is φ = 1082973239040.

The previous prime is 2166221655211. The next prime is 2166221655337. The reversal of 2166221655212 is 2125561226612.

It is a self number, because there is not a number n which added to its sum of digits gives 2166221655212.

It is not an unprimeable number, because it can be changed into a prime (2166221655211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34361714 + ... + 34424697.

It is an arithmetic number, because the mean of its divisors is an integer number (315947454718).

Almost surely, 2^{2166221655212} is an apocalyptic number.

It is an amenable number.

2166221655212 is a deficient number, since it is larger than the sum of its proper divisors (1625147801404).

2166221655212 is a wasteful number, since it uses less digits than its factorization.

2166221655212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68794288 (or 68794286 counting only the distinct ones).

The product of its digits is 172800, while the sum is 41.

The spelling of 2166221655212 in words is "two trillion, one hundred sixty-six billion, two hundred twenty-one million, six hundred fifty-five thousand, two hundred twelve".