25581123481 has 27 divisors (see below), whose sum is σ = 27116679103. Its totient is φ = 24131898080.

The previous prime is 25581123413. The next prime is 25581123487. The reversal of 25581123481 is 18432118552.

The square root of 25581123481 is 159941.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1232641881 + 24348481600 = 35109^2 + 156040^2 .

It is not a de Polignac number, because 25581123481 - 2¹⁵ = 25581090713 is a prime.

It is a super-2 number, since 2×25581123481² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25581123487) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 308206266 + ... + 308206348.

Almost surely, 2^25581123481 is an apocalyptic number.

25581123481 is the 159941-st square number.

25581123481 is the 79971-st centered octagonal number.

It is an amenable number.

25581123481 is a deficient number, since it is larger than the sum of its proper divisors (1535555622).

25581123481 is an frugal number, since it uses more digits than its factorization.

25581123481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342 (or 171 counting only the distinct ones).

The product of its digits is 76800, while the sum is 40.

The spelling of 25581123481 in words is "twenty-five billion, five hundred eighty-one million, one hundred twenty-three thousand, four hundred eighty-one".