25821744648 has 128 divisors (see below), whose sum is σ = 78272102400. Its totient is φ = 6934201344.

The previous prime is 25821744647. The next prime is 25821744659. The reversal of 25821744648 is 84644712852.

It is a self number, because there is not a number n which added to its sum of digits gives 25821744648.

It is not an unprimeable number, because it can be changed into a prime (25821744647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 373536 + ... + 437232.

It is an arithmetic number, because the mean of its divisors is an integer number (611500800).

Almost surely, 2^25821744648 is an apocalyptic number.

25821744648 is a gapful number since it is divisible by the number (28) 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 25821744648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39136051200).

25821744648 is an abundant number, since it is smaller than the sum of its proper divisors (52450357752).

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

25821744648 is a wasteful number, since it uses less digits than its factorization.

25821744648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63859 (or 63855 counting only the distinct ones).

The product of its digits is 3440640, while the sum is 51.

The spelling of 25821744648 in words is "twenty-five billion, eight hundred twenty-one million, seven hundred forty-four thousand, six hundred forty-eight".