2561261225 has 24 divisors (see below), whose sum is σ = 3367974168. Its totient is φ = 1925504000.

The previous prime is 2561261207. The next prime is 2561261231. The reversal of 2561261225 is 5221621652.

It can be written as a sum of positive squares in 12 ways, for example, as 14645929 + 2546615296 = 3827^2 + 50464^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2561261225 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2561261191 and 2561261200.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 293627 + ... + 302223.

It is an arithmetic number, because the mean of its divisors is an integer number (140332257).

Almost surely, 2^2561261225 is an apocalyptic number.

2561261225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2561261225 is a deficient number, since it is larger than the sum of its proper divisors (806712943).

2561261225 is a wasteful number, since it uses less digits than its factorization.

2561261225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9325 (or 9320 counting only the distinct ones).

The product of its digits is 14400, while the sum is 32.

The square root of 2561261225 is about 50608.9046018584. The cubic root of 2561261225 is about 1368.2053730016.

Adding to 2561261225 its reverse (5221621652), we get a palindrome (7782882877).

The spelling of 2561261225 in words is "two billion, five hundred sixty-one million, two hundred sixty-one thousand, two hundred twenty-five".