25405490881 has 9 divisors (see below), whose sum is σ = 26816193891. Its totient is φ = 24065490744.

The previous prime is 25405490839. The next prime is 25405490899. The reversal of 25405490881 is 18809450452.

The square root of 25405490881 is 159391.

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., 22025231281 + 3380259600 = 148409^2 + 58140^2 .

It is a de Polignac number, because none of the positive numbers 2^k-25405490881 is a prime.

It is a super-2 number, since 2×25405490881² (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 (25405410881) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3024235 + ... + 3032623.

It is an arithmetic number, because the mean of its divisors is an integer number (2979577099).

Almost surely, 2^25405490881 is an apocalyptic number.

25405490881 is the 159391-st square number.

25405490881 is the 79696-th centered octagonal number.

It is an amenable number.

25405490881 is a deficient number, since it is larger than the sum of its proper divisors (1410703010).

25405490881 is an frugal number, since it uses more digits than its factorization.

25405490881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16816 (or 8408 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 46.

The spelling of 25405490881 in words is "twenty-five billion, four hundred five million, four hundred ninety thousand, eight hundred eighty-one".