25999260644 has 54 divisors (see below), whose sum is σ = 53234240850. Its totient is φ = 11078242560.

The previous prime is 25999260631. The next prime is 25999260659. The reversal of 25999260644 is 44606299952.

It can be written as a sum of positive squares in 3 ways, for example, as 4357320100 + 21641940544 = 66010^2 + 147112^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 25999260644.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 6419132 + ... + 6423180.

It is an arithmetic number, because the mean of its divisors is an integer number (985819275).

Almost surely, 2^25999260644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25999260644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26617120425).

25999260644 is an abundant number, since it is smaller than the sum of its proper divisors (27234980206).

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

25999260644 is a wasteful number, since it uses less digits than its factorization.

25999260644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4429 (or 4239 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 56.

The spelling of 25999260644 in words is "twenty-five billion, nine hundred ninety-nine million, two hundred sixty thousand, six hundred forty-four".