220666813 has 2 divisors, whose sum is σ = 220666814. Its totient is φ = 220666812.

The previous prime is 220666781. The next prime is 220666819. The reversal of 220666813 is 318666022.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204004089 + 16662724 = 14283^2 + 4082^2 .

It is a cyclic number.

It is not a de Polignac number, because 220666813 - 2⁵ = 220666781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220666819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110333406 + 110333407.

It is an arithmetic number, because the mean of its divisors is an integer number (110333407).

Almost surely, 2^220666813 is an apocalyptic number.

It is an amenable number.

220666813 is a deficient number, since it is larger than the sum of its proper divisors (1).

220666813 is an equidigital number, since it uses as much as digits as its factorization.

220666813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 220666813 is about 14854.8582288758. The cubic root of 220666813 is about 604.2903712154.

The spelling of 220666813 in words is "two hundred twenty million, six hundred sixty-six thousand, eight hundred thirteen".