222661661 has 2 divisors, whose sum is σ = 222661662. Its totient is φ = 222661660.

The previous prime is 222661633. The next prime is 222661669. The reversal of 222661661 is 166166222.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190964761 + 31696900 = 13819^2 + 5630^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-222661661 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (222661669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111330830 + 111330831.

It is an arithmetic number, because the mean of its divisors is an integer number (111330831).

Almost surely, 2^222661661 is an apocalyptic number.

It is an amenable number.

222661661 is a deficient number, since it is larger than the sum of its proper divisors (1).

222661661 is an equidigital number, since it uses as much as digits as its factorization.

222661661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 32.

The square root of 222661661 is about 14921.8517952699. The cubic root of 222661661 is about 606.1058580190.

It can be divided in two parts, 222661 and 661, that added together give a palindrome (223322).

The spelling of 222661661 in words is "two hundred twenty-two million, six hundred sixty-one thousand, six hundred sixty-one".