25686820 has 12 divisors (see below), whose sum is σ = 53942364. Its totient is φ = 10274720.

The previous prime is 25686799. The next prime is 25686823. The reversal of 25686820 is 2868652.

It can be written as a sum of positive squares in 2 ways, for example, as 3709476 + 21977344 = 1926^2 + 4688^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 25686820.

It is not an unprimeable number, because it can be changed into a prime (25686823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 642151 + ... + 642190.

It is an arithmetic number, because the mean of its divisors is an integer number (4495197).

Almost surely, 2^25686820 is an apocalyptic number.

25686820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25686820 is an abundant number, since it is smaller than the sum of its proper divisors (28255544).

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

25686820 is a wasteful number, since it uses less digits than its factorization.

25686820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1284350 (or 1284348 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 25686820 is about 5068.2166488815. The cubic root of 25686820 is about 295.0553185545.

The spelling of 25686820 in words is "twenty-five million, six hundred eighty-six thousand, eight hundred twenty".