25566111648 has 672 divisors, whose sum is σ = 96565658112. Its totient is φ = 6466521600.

The previous prime is 25566111643. The next prime is 25566111671. The reversal of 25566111648 is 84611166552.

25566111648 is a `hidden beast` number, since 25 + 5 + 6 + 611 + 1 + 6 + 4 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25566111643) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 77238843 + ... + 77239173.

It is an arithmetic number, because the mean of its divisors is an integer number (143698896).

Almost surely, 2^25566111648 is an apocalyptic number.

25566111648 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 25566111648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48282829056).

25566111648 is an abundant number, since it is smaller than the sum of its proper divisors (70999546464).

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

25566111648 is a wasteful number, since it uses less digits than its factorization.

25566111648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420 (or 397 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The spelling of 25566111648 in words is "twenty-five billion, five hundred sixty-six million, one hundred eleven thousand, six hundred forty-eight".