25458640 has 20 divisors (see below), whose sum is σ = 59191524. Its totient is φ = 10183424.

The previous prime is 25458637. The next prime is 25458647. The reversal of 25458640 is 4685452.

It can be written as a sum of positive squares in 2 ways, for example, as 7683984 + 17774656 = 2772^2 + 4216^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 25458596 and 25458605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25458647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159037 + ... + 159196.

Almost surely, 2^25458640 is an apocalyptic number.

25458640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25458640 is an abundant number, since it is smaller than the sum of its proper divisors (33732884).

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

25458640 is a wasteful number, since it uses less digits than its factorization.

25458640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318246 (or 318240 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 34.

The square root of 25458640 is about 5045.6555570114. The cubic root of 25458640 is about 294.1790446881.

The spelling of 25458640 in words is "twenty-five million, four hundred fifty-eight thousand, six hundred forty".