25780205550 has 96 divisors (see below), whose sum is σ = 70324141824. Its totient is φ = 6249698400.

The previous prime is 25780205531. The next prime is 25780205551. The reversal of 25780205550 is 5550208752.

It is a junction number, because it is equal to n+sod(n) for n = 25780205499 and 25780205508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25780205551) 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 47 ways as a sum of consecutive naturals, for example, 135087 + ... + 264213.

It is an arithmetic number, because the mean of its divisors is an integer number (732543144).

Almost surely, 2^25780205550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25780205550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35162070912).

25780205550 is an abundant number, since it is smaller than the sum of its proper divisors (44543936274).

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

25780205550 is a wasteful number, since it uses less digits than its factorization.

25780205550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129175 (or 129148 counting only the distinct ones).

The product of its (nonzero) digits is 140000, while the sum is 39.

The spelling of 25780205550 in words is "twenty-five billion, seven hundred eighty million, two hundred five thousand, five hundred fifty".