25505440000 has 180 divisors, whose sum is σ = 67368157164. Its totient is φ = 9601024000.

The previous prime is 25505439961. The next prime is 25505440007. The reversal of 25505440000 is 4450552.

It can be written as a sum of positive squares in 10 ways, for example, as 21162102784 + 4343337216 = 145472^2 + 65904^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (25505440007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2715312 + ... + 2724688.

Almost surely, 2^25505440000 is an apocalyptic number.

25505440000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25505440000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33684078582).

25505440000 is an abundant number, since it is smaller than the sum of its proper divisors (41862717164).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25505440000 is an frugal number, since it uses more digits than its factorization.

25505440000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9430 (or 9401 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 25.

Adding to 25505440000 its reverse (4450552), we get a palindrome (25509890552).

The spelling of 25505440000 in words is "twenty-five billion, five hundred five million, four hundred forty thousand".