221422121 has 8 divisors (see below), whose sum is σ = 224195400. Its totient is φ = 218655360.

The previous prime is 221422111. The next prime is 221422129. The reversal of 221422121 is 121224122.

It can be written as a sum of positive squares in 4 ways, for example, as 35236096 + 186186025 = 5936^2 + 13645^2 .

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 221422121 - 2¹⁸ = 221159977 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221422121.

It is not an unprimeable number, because it can be changed into a prime (221422129) 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, 126311 + ... + 128051.

It is an arithmetic number, because the mean of its divisors is an integer number (28024425).

Almost surely, 2^221422121 is an apocalyptic number.

It is an amenable number.

221422121 is a deficient number, since it is larger than the sum of its proper divisors (2773279).

221422121 is a wasteful number, since it uses less digits than its factorization.

221422121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3259.

The product of its digits is 128, while the sum is 17.

The square root of 221422121 is about 14880.2594399426. The cubic root of 221422121 is about 604.9790498858.

Adding to 221422121 its reverse (121224122), we get a palindrome (342646243).

The spelling of 221422121 in words is "two hundred twenty-one million, four hundred twenty-two thousand, one hundred twenty-one".