221661166122 has 24 divisors (see below), whose sum is σ = 523926393120. Its totient is φ = 67170050280.

The previous prime is 221661165967. The next prime is 221661166147.

221661166122 is a `hidden beast` number, since 2 + 2 + 16 + 611 + 6 + 6 + 1 + 22 = 666.

221661166122 is nontrivially palindromic in base 10.

221661166122 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 559750222 + ... + 559750617.

It is an arithmetic number, because the mean of its divisors is an integer number (21830266380).

Almost surely, 2^221661166122 is an apocalyptic number.

221661166122 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

221661166122 is an abundant number, since it is smaller than the sum of its proper divisors (302265226998).

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

221661166122 is a wasteful number, since it uses less digits than its factorization.

221661166122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1119500858 (or 1119500855 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

It can be divided in two parts, 221661 and 166122, that added together give a palindrome (387783).

The spelling of 221661166122 in words is "two hundred twenty-one billion, six hundred sixty-one million, one hundred sixty-six thousand, one hundred twenty-two".