221001102212221 has 8 divisors (see below), whose sum is σ = 234001632828600. Its totient is φ = 208000623349248.

The previous prime is 221001102212213. The next prime is 221001102212243. The reversal of 221001102212221 is 122212201100122.

It can be written as a sum of positive squares in 4 ways, for example, as 2829591615321 + 218171510596900 = 1682139^2 + 14770630^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221001102212221 - 2³ = 221001102212213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001102215221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3968946 + ... + 21395203.

It is an arithmetic number, because the mean of its divisors is an integer number (29250204103575).

Almost surely, 2^{221001102212221} is an apocalyptic number.

It is an amenable number.

221001102212221 is a deficient number, since it is larger than the sum of its proper divisors (13000530616379).

221001102212221 is a wasteful number, since it uses less digits than its factorization.

221001102212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25876703.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 221001102212221 its reverse (122212201100122), we get a palindrome (343213303312343).

The spelling of 221001102212221 in words is "two hundred twenty-one trillion, one billion, one hundred two million, two hundred twelve thousand, two hundred twenty-one".