25544644553 has 4 divisors (see below), whose sum is σ = 25545266820. Its totient is φ = 25544022288.

The previous prime is 25544644507. The next prime is 25544644561. The reversal of 25544644553 is 35544644552.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 108222409 + 25436422144 = 10403^2 + 159488^2 .

It is a cyclic number.

It is not a de Polignac number, because 25544644553 - 2²⁸ = 25276209097 is a prime.

It is a super-2 number, since 2×25544644553² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25544644498 and 25544644507.

It is not an unprimeable number, because it can be changed into a prime (25544644253) 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 3 ways as a sum of consecutive naturals, for example, 244850 + ... + 333227.

It is an arithmetic number, because the mean of its divisors is an integer number (6386316705).

Almost surely, 2^25544644553 is an apocalyptic number.

It is an amenable number.

25544644553 is a deficient number, since it is larger than the sum of its proper divisors (622267).

25544644553 is an equidigital number, since it uses as much as digits as its factorization.

25544644553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 622266.

The product of its digits is 5760000, while the sum is 47.

Subtracting 25544644553 from its reverse (35544644552), we obtain a palindrome (9999999999).

The spelling of 25544644553 in words is "twenty-five billion, five hundred forty-four million, six hundred forty-four thousand, five hundred fifty-three".