25783966823581 has 2 divisors, whose sum is σ = 25783966823582. Its totient is φ = 25783966823580.

The previous prime is 25783966823567. The next prime is 25783966823591. The reversal of 25783966823581 is 18532866938752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20567041308100 + 5216925515481 = 4535090^2 + 2284059^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25783966823581 is a prime.

It is a super-2 number, since 2×25783966823581² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25783966823591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12891983411790 + 12891983411791.

It is an arithmetic number, because the mean of its divisors is an integer number (12891983411791).

Almost surely, 2^{25783966823581} is an apocalyptic number.

It is an amenable number.

25783966823581 is a deficient number, since it is larger than the sum of its proper divisors (1).

25783966823581 is an equidigital number, since it uses as much as digits as its factorization.

25783966823581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1045094400, while the sum is 73.

The spelling of 25783966823581 in words is "twenty-five trillion, seven hundred eighty-three billion, nine hundred sixty-six million, eight hundred twenty-three thousand, five hundred eighty-one".