25660240 has 40 divisors (see below), whose sum is σ = 61279560. Its totient is φ = 9985536.

The previous prime is 25660231. The next prime is 25660247. The reversal of 25660240 is 4206652.

It can be written as a sum of positive squares in 4 ways, for example, as 6370576 + 19289664 = 2524^2 + 4392^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25660247) 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, 1375 + ... + 7294.

It is an arithmetic number, because the mean of its divisors is an integer number (1531989).

Almost surely, 2^25660240 is an apocalyptic number.

25660240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25660240 is an abundant number, since it is smaller than the sum of its proper divisors (35619320).

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

25660240 is a wasteful number, since it uses less digits than its factorization.

25660240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8719 (or 8713 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 25660240 is about 5065.5937460479. The cubic root of 25660240 is about 294.9535117781.

Adding to 25660240 its reverse (4206652), we get a palindrome (29866892).

The spelling of 25660240 in words is "twenty-five million, six hundred sixty thousand, two hundred forty".