2221545121 has 4 divisors (see below), whose sum is σ = 2237527600. Its totient is φ = 2205562644.

The previous prime is 2221545103. The next prime is 2221545127. The reversal of 2221545121 is 1215451222.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2221545121 - 2⁵ = 2221545089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2221545127) 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, 7991031 + ... + 7991308.

It is an arithmetic number, because the mean of its divisors is an integer number (559381900).

Almost surely, 2^2221545121 is an apocalyptic number.

It is an amenable number.

2221545121 is a deficient number, since it is larger than the sum of its proper divisors (15982479).

2221545121 is a wasteful number, since it uses less digits than its factorization.

2221545121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15982478.

The product of its digits is 1600, while the sum is 25.

The square root of 2221545121 is about 47133.2697889718. The cubic root of 2221545121 is about 1304.8233288429.

Adding to 2221545121 its reverse (1215451222), we get a palindrome (3436996343).

The spelling of 2221545121 in words is "two billion, two hundred twenty-one million, five hundred forty-five thousand, one hundred twenty-one".