25565863680 has 864 divisors, whose sum is σ = 109163335680. Its totient is φ = 5643509760.

The previous prime is 25565863637. The next prime is 25565863681. The reversal of 25565863680 is 8636856552.

25565863680 is a `hidden beast` number, since 2 + 5 + 56 + 586 + 3 + 6 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a super-2 number, since 2×25565863680² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25565863681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 52496397 + ... + 52496883.

Almost surely, 2^25565863680 is an apocalyptic number.

25565863680 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 25565863680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54581667840).

25565863680 is an abundant number, since it is smaller than the sum of its proper divisors (83597472000).

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

25565863680 is a wasteful number, since it uses less digits than its factorization.

25565863680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 562 (or 535 counting only the distinct ones).

The product of its (nonzero) digits is 10368000, while the sum is 54.

The spelling of 25565863680 in words is "twenty-five billion, five hundred sixty-five million, eight hundred sixty-three thousand, six hundred eighty".