25813413758581 has 4 divisors (see below), whose sum is σ = 26511073589932. Its totient is φ = 25115753927232.

The previous prime is 25813413758563. The next prime is 25813413758593. The reversal of 25813413758581 is 18585731431852.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10360731378481 + 15452682380100 = 3218809^2 + 3930990^2 .

It is a cyclic number.

It is not a de Polignac number, because 25813413758581 - 2⁵ = 25813413758549 is a prime.

It is a super-2 number, since 2×25813413758581² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25813413758551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 348829915620 + ... + 348829915693.

It is an arithmetic number, because the mean of its divisors is an integer number (6627768397483).

Almost surely, 2^{25813413758581} is an apocalyptic number.

It is an amenable number.

25813413758581 is a deficient number, since it is larger than the sum of its proper divisors (697659831351).

25813413758581 is an equidigital number, since it uses as much as digits as its factorization.

25813413758581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697659831350.

The product of its digits is 32256000, while the sum is 61.

The spelling of 25813413758581 in words is "twenty-five trillion, eight hundred thirteen billion, four hundred thirteen million, seven hundred fifty-eight thousand, five hundred eighty-one".