2122212221 has 8 divisors (see below), whose sum is σ = 2253079224. Its totient is φ = 1992015360.

The previous prime is 2122212179. The next prime is 2122212227. The reversal of 2122212221 is 1222122212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 365344996 + 1756867225 = 19114^2 + 41915^2 .

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 2122212221 - 2¹⁰ = 2122211197 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 2122212221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2122212227) 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, 161000 + ... + 173681.

It is an arithmetic number, because the mean of its divisors is an integer number (281634903).

Almost surely, 2^2122212221 is an apocalyptic number.

It is an amenable number.

2122212221 is a deficient number, since it is larger than the sum of its proper divisors (130867003).

2122212221 is a wasteful number, since it uses less digits than its factorization.

2122212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335071.

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

The square root of 2122212221 is about 46067.4746540333. The cubic root of 2122212221 is about 1285.0783402909.

Adding to 2122212221 its reverse (1222122212), we get a palindrome (3344334433).

Subtracting from 2122212221 its reverse (1222122212), we obtain a palindrome (900090009).

It can be divided in two parts, 2 and 122212221, that multiplied together give a palindrome (244424442).

The spelling of 2122212221 in words is "two billion, one hundred twenty-two million, two hundred twelve thousand, two hundred twenty-one".