25971865920 has 1890 divisors, whose sum is σ = 127913955246. Its totient is φ = 4981616640.

The previous prime is 25971865867. The next prime is 25971865939. The reversal of 25971865920 is 2956817952.

It can be written as a sum of positive squares in 3 ways, for example, as 122943744 + 25848922176 = 11088^2 + 160776^2 .

It is a tau number, because it is divible by the number of its divisors (1890).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 269 ways as a sum of consecutive naturals, for example, 1997835834 + ... + 1997835846.

Almost surely, 2^25971865920 is an apocalyptic number.

25971865920 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 25971865920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63956977623).

25971865920 is an abundant number, since it is smaller than the sum of its proper divisors (101942089326).

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

25971865920 is a wasteful number, since it uses less digits than its factorization.

25971865920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The spelling of 25971865920 in words is "twenty-five billion, nine hundred seventy-one million, eight hundred sixty-five thousand, nine hundred twenty".