221844281 has 2 divisors, whose sum is σ = 221844282. Its totient is φ = 221844280.

The previous prime is 221844253. The next prime is 221844283. The reversal of 221844281 is 182448122.

221844281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 221741881 + 102400 = 14891^2 + 320^2 .

It is a cyclic number.

It is not a de Polignac number, because 221844281 - 2¹⁴ = 221827897 is a prime.

It is a super-2 number, since 2×221844281² = 98429770024813922, which contains 22 as substring.

Together with 221844283, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221844283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110922140 + 110922141.

It is an arithmetic number, because the mean of its divisors is an integer number (110922141).

Almost surely, 2^221844281 is an apocalyptic number.

It is an amenable number.

221844281 is a deficient number, since it is larger than the sum of its proper divisors (1).

221844281 is an equidigital number, since it uses as much as digits as its factorization.

221844281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8192, while the sum is 32.

The square root of 221844281 is about 14894.4379215867. The cubic root of 221844281 is about 605.3632870368.

The spelling of 221844281 in words is "two hundred twenty-one million, eight hundred forty-four thousand, two hundred eighty-one".