221666126112 has 54 divisors (see below), whose sum is σ = 630385768467. Its totient is φ = 73886045376.

The previous prime is 221666126089. The next prime is 221666126119. The reversal of 221666126112 is 211621666122.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 110833063056 + 110833063056 = 332916^2 + 332916^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=332916.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is not an unprimeable number, because it can be changed into a prime (221666126119) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 7976113 + ... + 8003855.

Almost surely, 2^221666126112 is an apocalyptic number.

It is an amenable number.

221666126112 is an abundant number, since it is smaller than the sum of its proper divisors (408719642355).

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

221666126112 is an frugal number, since it uses more digits than its factorization.

221666126112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55502 (or 27748 counting only the distinct ones).

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

The spelling of 221666126112 in words is "two hundred twenty-one billion, six hundred sixty-six million, one hundred twenty-six thousand, one hundred twelve".