2121224121 has 6 divisors (see below), whose sum is σ = 3063990410. Its totient is φ = 1414149408.

The previous prime is 2121224117. The next prime is 2121224123. The reversal of 2121224121 is 1214221212.

It can be written as a sum of positive squares in only one way, i.e., 1406250000 + 714974121 = 37500^2 + 26739^2 .

It is not a de Polignac number, because 2121224121 - 2² = 2121224117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121224094 and 2121224103.

It is not an unprimeable number, because it can be changed into a prime (2121224123) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 117845776 + ... + 117845793.

Almost surely, 2^2121224121 is an apocalyptic number.

It is an amenable number.

2121224121 is a deficient number, since it is larger than the sum of its proper divisors (942766289).

2121224121 is a wasteful number, since it uses less digits than its factorization.

2121224121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235691575 (or 235691572 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 2121224121 is about 46056.7489191324. The cubic root of 2121224121 is about 1284.8788655766.

Adding to 2121224121 its reverse (1214221212), we get a palindrome (3335445333).

The spelling of 2121224121 in words is "two billion, one hundred twenty-one million, two hundred twenty-four thousand, one hundred twenty-one".