2561305830749 has 2 divisors, whose sum is σ = 2561305830750. Its totient is φ = 2561305830748.

The previous prime is 2561305830709. The next prime is 2561305830763. The reversal of 2561305830749 is 9470385031652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2285896038724 + 275409792025 = 1511918^2 + 524795^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2561305830749 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2561305830749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2561305830709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280652915374 + 1280652915375.

It is an arithmetic number, because the mean of its divisors is an integer number (1280652915375).

It is a 1-persistent number, because it is pandigital, but 2⋅2561305830749 = 5122611661498 is not.

Almost surely, 2^{2561305830749} is an apocalyptic number.

It is an amenable number.

2561305830749 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561305830749 is an equidigital number, since it uses as much as digits as its factorization.

2561305830749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5443200, while the sum is 53.

The spelling of 2561305830749 in words is "two trillion, five hundred sixty-one billion, three hundred five million, eight hundred thirty thousand, seven hundred forty-nine".