25528403261681 has 2 divisors, whose sum is σ = 25528403261682. Its totient is φ = 25528403261680.

The previous prime is 25528403261611. The next prime is 25528403261737. The reversal of 25528403261681 is 18616230482552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20718737582656 + 4809665679025 = 4551784^2 + 2193095^2 .

It is a cyclic number.

It is not a de Polignac number, because 25528403261681 - 2⁴² = 21130356750577 is a prime.

It is a super-2 number, since 2×25528403261681² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25528403261611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12764201630840 + 12764201630841.

It is an arithmetic number, because the mean of its divisors is an integer number (12764201630841).

Almost surely, 2^{25528403261681} is an apocalyptic number.

It is an amenable number.

25528403261681 is a deficient number, since it is larger than the sum of its proper divisors (1).

25528403261681 is an equidigital number, since it uses as much as digits as its factorization.

25528403261681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5529600, while the sum is 53.

The spelling of 25528403261681 in words is "twenty-five trillion, five hundred twenty-eight billion, four hundred three million, two hundred sixty-one thousand, six hundred eighty-one".