2153111221 has 4 divisors (see below), whose sum is σ = 2153565792. Its totient is φ = 2152656652.

The previous prime is 2153111209. The next prime is 2153111243. The reversal of 2153111221 is 1221113512.

2153111221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2153111221 - 2⁵ = 2153111189 is a prime.

It is a super-2 number, since 2×2153111221² = 9271775859992221682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2153111201) 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, 220105 + ... + 229678.

It is an arithmetic number, because the mean of its divisors is an integer number (538391448).

Almost surely, 2^2153111221 is an apocalyptic number.

It is an amenable number.

2153111221 is a deficient number, since it is larger than the sum of its proper divisors (454571).

2153111221 is an equidigital number, since it uses as much as digits as its factorization.

2153111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454570.

The product of its digits is 120, while the sum is 19.

The square root of 2153111221 is about 46401.6295080248. The cubic root of 2153111221 is about 1291.2851445624.

Adding to 2153111221 its reverse (1221113512), we get a palindrome (3374224733).

The spelling of 2153111221 in words is "two billion, one hundred fifty-three million, one hundred eleven thousand, two hundred twenty-one".