25820643456 has 448 divisors, whose sum is σ = 82356937920. Its totient is φ = 8041752576.

The previous prime is 25820643451. The next prime is 25820643463. The reversal of 25820643456 is 65434602852.

25820643456 is a `hidden beast` number, since 2 + 5 + 8 + 206 + 434 + 5 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (25820643451) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 113747215 + ... + 113747441.

Almost surely, 2^25820643456 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 25820643456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41178468960).

25820643456 is an abundant number, since it is smaller than the sum of its proper divisors (56536294464).

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

25820643456 is an equidigital number, since it uses as much as digits as its factorization.

25820643456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335 (or 308 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 45.

The spelling of 25820643456 in words is "twenty-five billion, eight hundred twenty million, six hundred forty-three thousand, four hundred fifty-six".