221200000121 has 4 divisors (see below), whose sum is σ = 234211764852. Its totient is φ = 208188235392.

The previous prime is 221200000103. The next prime is 221200000123. The reversal of 221200000121 is 121000002122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 149932358521 + 71267641600 = 387211^2 + 266960^2 .

It is a cyclic number.

It is not a de Polignac number, because 221200000121 - 2²⁶ = 221132891257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221200000123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6505882340 + ... + 6505882373.

It is an arithmetic number, because the mean of its divisors is an integer number (58552941213).

Almost surely, 2^221200000121 is an apocalyptic number.

It is an amenable number.

221200000121 is a deficient number, since it is larger than the sum of its proper divisors (13011764731).

221200000121 is a wasteful number, since it uses less digits than its factorization.

221200000121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13011764730.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 221200000121 its reverse (121000002122), we get a palindrome (342200002243).

The spelling of 221200000121 in words is "two hundred twenty-one billion, two hundred million, one hundred twenty-one", and thus it is an aban number.