221606573 has 2 divisors, whose sum is σ = 221606574. Its totient is φ = 221606572.

The previous prime is 221606531. The next prime is 221606669. The reversal of 221606573 is 375606122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204976489 + 16630084 = 14317^2 + 4078^2 .

It is a cyclic number.

It is not a de Polignac number, because 221606573 - 2⁸ = 221606317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221606513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110803286 + 110803287.

It is an arithmetic number, because the mean of its divisors is an integer number (110803287).

Almost surely, 2^221606573 is an apocalyptic number.

It is an amenable number.

221606573 is a deficient number, since it is larger than the sum of its proper divisors (1).

221606573 is an equidigital number, since it uses as much as digits as its factorization.

221606573 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 32.

The square root of 221606573 is about 14886.4560255287. The cubic root of 221606573 is about 605.1469924919.

The spelling of 221606573 in words is "two hundred twenty-one million, six hundred six thousand, five hundred seventy-three".