2152311221 has 4 divisors (see below), whose sum is σ = 2152481100. Its totient is φ = 2152141344.

The previous prime is 2152311211. The next prime is 2152311229. The reversal of 2152311221 is 1221132512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2128438225 + 23872996 = 46135^2 + 4886^2 .

It is a cyclic number.

It is not a de Polignac number, because 2152311221 - 2²² = 2148116917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2152311193 and 2152311202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2152311229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64256 + ... + 91833.

It is an arithmetic number, because the mean of its divisors is an integer number (538120275).

Almost surely, 2^2152311221 is an apocalyptic number.

It is an amenable number.

2152311221 is a deficient number, since it is larger than the sum of its proper divisors (169879).

2152311221 is a wasteful number, since it uses less digits than its factorization.

2152311221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169878.

The product of its digits is 240, while the sum is 20.

The square root of 2152311221 is about 46393.0083202200. The cubic root of 2152311221 is about 1291.1251967817.

Adding to 2152311221 its reverse (1221132512), we get a palindrome (3373443733).

The spelling of 2152311221 in words is "two billion, one hundred fifty-two million, three hundred eleven thousand, two hundred twenty-one".