25666660 has 12 divisors (see below), whose sum is σ = 53900028. Its totient is φ = 10266656.

The previous prime is 25666639. The next prime is 25666661. The reversal of 25666660 is 6666652.

It can be written as a sum of positive squares in 2 ways, for example, as 9474084 + 16192576 = 3078^2 + 4024^2 .

It is not an unprimeable number, because it can be changed into a prime (25666661) 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 3 ways as a sum of consecutive naturals, for example, 641647 + ... + 641686.

It is an arithmetic number, because the mean of its divisors is an integer number (4491669).

Almost surely, 2^25666660 is an apocalyptic number.

25666660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25666660 is an abundant number, since it is smaller than the sum of its proper divisors (28233368).

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

25666660 is a wasteful number, since it uses less digits than its factorization.

25666660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1283342 (or 1283340 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 37.

The square root of 25666660 is about 5066.2273932385. The cubic root of 25666660 is about 294.9781081140.

The spelling of 25666660 in words is "twenty-five million, six hundred sixty-six thousand, six hundred sixty".