6740667400661 has 2 divisors, whose sum is σ = 6740667400662. Its totient is φ = 6740667400660.

The previous prime is 6740667400619. The next prime is 6740667400763. The reversal of 6740667400661 is 1660047660476.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6495438418225 + 245228982436 = 2548615^2 + 495206^2 .

It is a cyclic number.

It is not a de Polignac number, because 6740667400661 - 2²⁶ = 6740600291797 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 (6740667400601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3370333700330 + 3370333700331.

It is an arithmetic number, because the mean of its divisors is an integer number (3370333700331).

Almost surely, 2^{6740667400661} is an apocalyptic number.

It is an amenable number.

6740667400661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6740667400661 is an equidigital number, since it uses as much as digits as its factorization.

6740667400661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6096384, while the sum is 53.

The spelling of 6740667400661 in words is "six trillion, seven hundred forty billion, six hundred sixty-seven million, four hundred thousand, six hundred sixty-one".