25597120081 has 27 divisors (see below), whose sum is σ = 28712874033. Its totient is φ = 22808316960.

The previous prime is 25597120079. The next prime is 25597120091. The reversal of 25597120081 is 18002179552.

The square root of 25597120081 is 159991.

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

It can be written as a sum of positive squares in 4 ways, for example, as 1186182481 + 24410937600 = 34441^2 + 156240^2 .

It is not a de Polignac number, because 25597120081 - 2¹ = 25597120079 is a prime.

It is a super-2 number, since 2×25597120081² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25597120061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 64476175 + ... + 64476571.

It is an arithmetic number, because the mean of its divisors is an integer number (1063439779).

Almost surely, 2^25597120081 is an apocalyptic number.

25597120081 is the 159991-st square number.

25597120081 is the 79996-th centered octagonal number.

It is an amenable number.

25597120081 is a deficient number, since it is larger than the sum of its proper divisors (3115753952).

25597120081 is an frugal number, since it uses more digits than its factorization.

25597120081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 882 (or 441 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 40.

The spelling of 25597120081 in words is "twenty-five billion, five hundred ninety-seven million, one hundred twenty thousand, eighty-one".