221220200121 has 16 divisors (see below), whose sum is σ = 295396485120. Its totient is φ = 147262122000.

The previous prime is 221220200107. The next prime is 221220200137. The reversal of 221220200121 is 121002022122.

It is not a de Polignac number, because 221220200121 - 2¹⁵ = 221220167353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221220200121.

It is not an unprimeable number, because it can be changed into a prime (221220200161) 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, 11720790 + ... + 11739648.

It is an arithmetic number, because the mean of its divisors is an integer number (18462280320).

Almost surely, 2^221220200121 is an apocalyptic number.

It is an amenable number.

221220200121 is a deficient number, since it is larger than the sum of its proper divisors (74176284999).

221220200121 is a wasteful number, since it uses less digits than its factorization.

221220200121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24436.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221220200121 its reverse (121002022122), we get a palindrome (342222222243).

The spelling of 221220200121 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred thousand, one hundred twenty-one".