25561549556 has 12 divisors (see below), whose sum is σ = 45466035300. Its totient is φ = 12571253760.

The previous prime is 25561549553. The next prime is 25561549597. The reversal of 25561549556 is 65594516552.

It can be written as a sum of positive squares in 2 ways, for example, as 13198333456 + 12363216100 = 114884^2 + 111190^2 .

It is a junction number, because it is equal to n+sod(n) for n = 25561549498 and 25561549507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25561549553) 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, 52379981 + ... + 52380468.

It is an arithmetic number, because the mean of its divisors is an integer number (3788836275).

Almost surely, 2^25561549556 is an apocalyptic number.

It is an amenable number.

25561549556 is a deficient number, since it is larger than the sum of its proper divisors (19904485744).

25561549556 is a wasteful number, since it uses less digits than its factorization.

25561549556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104760514 (or 104760512 counting only the distinct ones).

The product of its digits is 8100000, while the sum is 53.

The spelling of 25561549556 in words is "twenty-five billion, five hundred sixty-one million, five hundred forty-nine thousand, five hundred fifty-six".