2661666653309 has 2 divisors, whose sum is σ = 2661666653310. Its totient is φ = 2661666653308.

The previous prime is 2661666653291. The next prime is 2661666653341. The reversal of 2661666653309 is 9033566661662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2647382818084 + 14283835225 = 1627078^2 + 119515^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661666653309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2661666653389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330833326654 + 1330833326655.

It is an arithmetic number, because the mean of its divisors is an integer number (1330833326655).

Almost surely, 2^{2661666653309} is an apocalyptic number.

It is an amenable number.

2661666653309 is a deficient number, since it is larger than the sum of its proper divisors (1).

2661666653309 is an equidigital number, since it uses as much as digits as its factorization.

2661666653309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37791360, while the sum is 59.

The spelling of 2661666653309 in words is "two trillion, six hundred sixty-one billion, six hundred sixty-six million, six hundred fifty-three thousand, three hundred nine".