25656540 has 192 divisors, whose sum is σ = 91521024. Its totient is φ = 5225472.

The previous prime is 25656487. The next prime is 25656541. The reversal of 25656540 is 4565652.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25656541) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 201957 + ... + 202083.

It is an arithmetic number, because the mean of its divisors is an integer number (476672).

Almost surely, 2^25656540 is an apocalyptic number.

25656540 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 25656540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45760512).

25656540 is an abundant number, since it is smaller than the sum of its proper divisors (65864484).

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

25656540 is a wasteful number, since it uses less digits than its factorization.

25656540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196 (or 194 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 33.

The square root of 25656540 is about 5065.2285239661. The cubic root of 25656540 is about 294.9393344562.

The spelling of 25656540 in words is "twenty-five million, six hundred fifty-six thousand, five hundred forty".