221321297 has 2 divisors, whose sum is σ = 221321298. Its totient is φ = 221321296.

The previous prime is 221321281. The next prime is 221321323. The reversal of 221321297 is 792123122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 221295376 + 25921 = 14876^2 + 161^2 .

It is a cyclic number.

It is not a de Polignac number, because 221321297 - 2⁴ = 221321281 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221321267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110660648 + 110660649.

It is an arithmetic number, because the mean of its divisors is an integer number (110660649).

Almost surely, 2^221321297 is an apocalyptic number.

It is an amenable number.

221321297 is a deficient number, since it is larger than the sum of its proper divisors (1).

221321297 is an equidigital number, since it uses as much as digits as its factorization.

221321297 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 29.

The square root of 221321297 is about 14876.8712100361. The cubic root of 221321297 is about 604.8872107206.

The spelling of 221321297 in words is "two hundred twenty-one million, three hundred twenty-one thousand, two hundred ninety-seven".