221306473 has 2 divisors, whose sum is σ = 221306474. Its totient is φ = 221306472.

The previous prime is 221306461. The next prime is 221306531. The reversal of 221306473 is 374603122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 221027689 + 278784 = 14867^2 + 528^2 .

It is a cyclic number.

It is not a de Polignac number, because 221306473 - 2⁵ = 221306441 is a prime.

It is not a weakly prime, because it can be changed into another prime (221306443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110653236 + 110653237.

It is an arithmetic number, because the mean of its divisors is an integer number (110653237).

Almost surely, 2^221306473 is an apocalyptic number.

It is an amenable number.

221306473 is a deficient number, since it is larger than the sum of its proper divisors (1).

221306473 is an equidigital number, since it uses as much as digits as its factorization.

221306473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 28.

The square root of 221306473 is about 14876.3729786531. The cubic root of 221306473 is about 604.8737053955.

Adding to 221306473 its reverse (374603122), we get a palindrome (595909595).

The spelling of 221306473 in words is "two hundred twenty-one million, three hundred six thousand, four hundred seventy-three".