221666111412 has 12 divisors (see below), whose sum is σ = 517220926656. Its totient is φ = 73888703800.

The previous prime is 221666111363. The next prime is 221666111423. The reversal of 221666111412 is 214111666122.

221666111412 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9236087964 + ... + 9236087987.

It is an arithmetic number, because the mean of its divisors is an integer number (43101743888).

Almost surely, 2^221666111412 is an apocalyptic number.

It is an amenable number.

221666111412 is an abundant number, since it is smaller than the sum of its proper divisors (295554815244).

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

221666111412 is a wasteful number, since it uses less digits than its factorization.

221666111412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18472175958 (or 18472175956 counting only the distinct ones).

The product of its digits is 6912, while the sum is 33.

Adding to 221666111412 its reverse (214111666122), we get a palindrome (435777777534).

The spelling of 221666111412 in words is "two hundred twenty-one billion, six hundred sixty-six million, one hundred eleven thousand, four hundred twelve".