25508640 has 96 divisors (see below), whose sum is σ = 84611520. Its totient is φ = 6441984.

The previous prime is 25508597. The next prime is 25508641. The reversal of 25508640 is 4680552.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 25508598 and 25508607.

It is not an unprimeable number, because it can be changed into a prime (25508641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7722 + ... + 10518.

It is an arithmetic number, because the mean of its divisors is an integer number (881370).

Almost surely, 2^25508640 is an apocalyptic number.

25508640 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 25508640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42305760).

25508640 is an abundant number, since it is smaller than the sum of its proper divisors (59102880).

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

25508640 is a wasteful number, since it uses less digits than its factorization.

25508640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2834 (or 2826 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

The square root of 25508640 is about 5050.6078842056. The cubic root of 25508640 is about 294.3715050004.

The spelling of 25508640 in words is "twenty-five million, five hundred eight thousand, six hundred forty".