666220433 has 2 divisors, whose sum is σ = 666220434. Its totient is φ = 666220432.

The previous prime is 666220421. The next prime is 666220453. The reversal of 666220433 is 334022666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 595945744 + 70274689 = 24412^2 + 8383^2 .

It is a cyclic number.

It is not a de Polignac number, because 666220433 - 2⁴ = 666220417 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 666220433.

It is not a weakly prime, because it can be changed into another prime (666220453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333110216 + 333110217.

It is an arithmetic number, because the mean of its divisors is an integer number (333110217).

Almost surely, 2^666220433 is an apocalyptic number.

It is an amenable number.

666220433 is a deficient number, since it is larger than the sum of its proper divisors (1).

666220433 is an equidigital number, since it uses as much as digits as its factorization.

666220433 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 32.

The square root of 666220433 is about 25811.2462504235. The cubic root of 666220433 is about 873.3855107254.

The spelling of 666220433 in words is "six hundred sixty-six million, two hundred twenty thousand, four hundred thirty-three".