2666333561 has 2 divisors, whose sum is σ = 2666333562. Its totient is φ = 2666333560.

The previous prime is 2666333557. The next prime is 2666333563. The reversal of 2666333561 is 1653336662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2625947536 + 40386025 = 51244^2 + 6355^2 .

It is a cyclic number.

It is not a de Polignac number, because 2666333561 - 2² = 2666333557 is a prime.

Together with 2666333563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2666333563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1333166780 + 1333166781.

It is an arithmetic number, because the mean of its divisors is an integer number (1333166781).

Almost surely, 2^2666333561 is an apocalyptic number.

It is an amenable number.

2666333561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2666333561 is an equidigital number, since it uses as much as digits as its factorization.

2666333561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 349920, while the sum is 41.

The square root of 2666333561 is about 51636.5525669559. The cubic root of 2666333561 is about 1386.6648056545.

The spelling of 2666333561 in words is "two billion, six hundred sixty-six million, three hundred thirty-three thousand, five hundred sixty-one".