221531449 has 2 divisors, whose sum is σ = 221531450. Its totient is φ = 221531448.

The previous prime is 221531447. The next prime is 221531483. The reversal of 221531449 is 944135122.

221531449 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 213306025 + 8225424 = 14605^2 + 2868^2 .

It is a cyclic number.

It is not a de Polignac number, because 221531449 - 2¹ = 221531447 is a prime.

Together with 221531447, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221531449.

It is not a weakly prime, because it can be changed into another prime (221531447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110765724 + 110765725.

It is an arithmetic number, because the mean of its divisors is an integer number (110765725).

Almost surely, 2^221531449 is an apocalyptic number.

It is an amenable number.

221531449 is a deficient number, since it is larger than the sum of its proper divisors (1).

221531449 is an equidigital number, since it uses as much as digits as its factorization.

221531449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 31.

The square root of 221531449 is about 14883.9325784552. The cubic root of 221531449 is about 605.0786037251.

The spelling of 221531449 in words is "two hundred twenty-one million, five hundred thirty-one thousand, four hundred forty-nine".