25820155440 has 240 divisors, whose sum is σ = 90339575040. Its totient is φ = 6601512960.

The previous prime is 25820155421. The next prime is 25820155447. The reversal of 25820155440 is 4455102852.

25820155440 is a `hidden beast` number, since 2 + 5 + 8 + 201 + 5 + 5 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 25820155395 and 25820155404.

It is not an unprimeable number, because it can be changed into a prime (25820155447) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2427574 + ... + 2438186.

It is an arithmetic number, because the mean of its divisors is an integer number (376414896).

Almost surely, 2^25820155440 is an apocalyptic number.

25820155440 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 25820155440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45169787520).

25820155440 is an abundant number, since it is smaller than the sum of its proper divisors (64519419600).

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

25820155440 is a wasteful number, since it uses less digits than its factorization.

25820155440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10772 (or 10763 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 36.

The spelling of 25820155440 in words is "twenty-five billion, eight hundred twenty million, one hundred fifty-five thousand, four hundred forty".