25544644551 has 48 divisors (see below), whose sum is σ = 38087981568. Its totient is φ = 16487452800.

The previous prime is 25544644507. The next prime is 25544644561. The reversal of 25544644551 is 15544644552.

25544644551 is a `hidden beast` number, since 2 + 5 + 54 + 4 + 6 + 44 + 551 = 666.

It is not a de Polignac number, because 25544644551 - 2⁷ = 25544644423 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25544644497 and 25544644506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25544644561) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 46699260 + ... + 46699806.

It is an arithmetic number, because the mean of its divisors is an integer number (793499616).

Almost surely, 2^25544644551 is an apocalyptic number.

25544644551 is a deficient number, since it is larger than the sum of its proper divisors (12543337017).

25544644551 is a wasteful number, since it uses less digits than its factorization.

25544644551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1332 (or 1329 counting only the distinct ones).

The product of its digits is 1920000, while the sum is 45.

Subtracting from 25544644551 its reverse (15544644552), we obtain a palindrome (9999999999).

The spelling of 25544644551 in words is "twenty-five billion, five hundred forty-four million, six hundred forty-four thousand, five hundred fifty-one".