2681993720261 has 2 divisors, whose sum is σ = 2681993720262. Its totient is φ = 2681993720260.

The previous prime is 2681993720207. The next prime is 2681993720281. The reversal of 2681993720261 is 1620273991862.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2667035207236 + 14958513025 = 1633106^2 + 122305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2681993720261 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2681993720197 and 2681993720206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2681993720281) 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, 1340996860130 + 1340996860131.

It is an arithmetic number, because the mean of its divisors is an integer number (1340996860131).

Almost surely, 2^{2681993720261} is an apocalyptic number.

It is an amenable number.

2681993720261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2681993720261 is an equidigital number, since it uses as much as digits as its factorization.

2681993720261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3919104, while the sum is 56.

The spelling of 2681993720261 in words is "two trillion, six hundred eighty-one billion, nine hundred ninety-three million, seven hundred twenty thousand, two hundred sixty-one".