2668612721 has 2 divisors, whose sum is σ = 2668612722. Its totient is φ = 2668612720.

The previous prime is 2668612669. The next prime is 2668612759. The reversal of 2668612721 is 1272168662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2125210000 + 543402721 = 46100^2 + 23311^2 .

It is a cyclic number.

It is not a de Polignac number, because 2668612721 - 2¹⁸ = 2668350577 is a prime.

It is not a weakly prime, because it can be changed into another prime (2668618721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1334306360 + 1334306361.

It is an arithmetic number, because the mean of its divisors is an integer number (1334306361).

Almost surely, 2^2668612721 is an apocalyptic number.

It is an amenable number.

2668612721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2668612721 is an equidigital number, since it uses as much as digits as its factorization.

2668612721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 41.

The square root of 2668612721 is about 51658.6171030545. The cubic root of 2668612721 is about 1387.0597963549.

The spelling of 2668612721 in words is "two billion, six hundred sixty-eight million, six hundred twelve thousand, seven hundred twenty-one".