2144021221 has 2 divisors, whose sum is σ = 2144021222. Its totient is φ = 2144021220.

The previous prime is 2144021219. The next prime is 2144021251. The reversal of 2144021221 is 1221204412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1259256196 + 884765025 = 35486^2 + 29745^2 .

It is a cyclic number.

It is not a de Polignac number, because 2144021221 - 2¹ = 2144021219 is a prime.

Together with 2144021219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2144021251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1072010610 + 1072010611.

It is an arithmetic number, because the mean of its divisors is an integer number (1072010611).

Almost surely, 2^2144021221 is an apocalyptic number.

It is an amenable number.

2144021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2144021221 is an equidigital number, since it uses as much as digits as its factorization.

2144021221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 2144021221 is about 46303.5767624921. The cubic root of 2144021221 is about 1289.4653997389.

Adding to 2144021221 its reverse (1221204412), we get a palindrome (3365225633).

The spelling of 2144021221 in words is "two billion, one hundred forty-four million, twenty-one thousand, two hundred twenty-one".