25597440 has 240 divisors, whose sum is σ = 97667856. Its totient is φ = 6144000.

The previous prime is 25597423. The next prime is 25597441. The reversal of 25597440 is 4479552.

25597440 is a `hidden beast` number, since 25 + 597 + 4 + 40 = 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 = 25597395 and 25597404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25597441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 253390 + ... + 253490.

Almost surely, 2^25597440 is an apocalyptic number.

25597440 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 25597440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48833928).

25597440 is an abundant number, since it is smaller than the sum of its proper divisors (72070416).

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

25597440 is a wasteful number, since it uses less digits than its factorization.

25597440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 25597440 is about 5059.3912677317. The cubic root of 25597440 is about 294.7126954797.

It can be divided in two parts, 2559 and 7440, that added together give a palindrome (9999).

The spelling of 25597440 in words is "twenty-five million, five hundred ninety-seven thousand, four hundred forty".