25521040 has 40 divisors (see below), whose sum is σ = 60353280. Its totient is φ = 10033536.

The previous prime is 25521011. The next prime is 25521043. The reversal of 25521040 is 4012552.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 25520999 and 25521017.

It is not an unprimeable number, because it can be changed into a prime (25521043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2017 + ... + 7423.

It is an arithmetic number, because the mean of its divisors is an integer number (1508832).

Almost surely, 2^25521040 is an apocalyptic number.

25521040 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 25521040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30176640).

25521040 is an abundant number, since it is smaller than the sum of its proper divisors (34832240).

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

25521040 is a wasteful number, since it uses less digits than its factorization.

25521040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5479 (or 5473 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 25521040 is about 5051.8353100631. The cubic root of 25521040 is about 294.4191962317.

Adding to 25521040 its reverse (4012552), we get a palindrome (29533592).

The spelling of 25521040 in words is "twenty-five million, five hundred twenty-one thousand, forty".