221220021112001 has 16 divisors (see below), whose sum is σ = 242319653868240. Its totient is φ = 201019483822080.

The previous prime is 221220021111997. The next prime is 221220021112003. The reversal of 221220021112001 is 100211120022122.

It can be written as a sum of positive squares in 8 ways, for example, as 7964818484401 + 213255202627600 = 2822201^2 + 14603260^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220021112001 - 2² = 221220021111997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221220021112003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3382061 + ... + 21304421.

It is an arithmetic number, because the mean of its divisors is an integer number (15144978366765).

Almost surely, 2^{221220021112001} is an apocalyptic number.

It is an amenable number.

221220021112001 is a deficient number, since it is larger than the sum of its proper divisors (21099632756239).

221220021112001 is a wasteful number, since it uses less digits than its factorization.

221220021112001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17947444.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221220021112001 its reverse (100211120022122), we get a palindrome (321431141134123).

The spelling of 221220021112001 in words is "two hundred twenty-one trillion, two hundred twenty billion, twenty-one million, one hundred twelve thousand, one".