12865820 has 24 divisors (see below), whose sum is σ = 29474928. Its totient is φ = 4678400.

The previous prime is 12865813. The next prime is 12865829. The reversal of 12865820 is 2856821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12865829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29021 + ... + 29460.

It is an arithmetic number, because the mean of its divisors is an integer number (1228122).

Almost surely, 2^12865820 is an apocalyptic number.

12865820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12865820 is an abundant number, since it is smaller than the sum of its proper divisors (16609108).

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

12865820 is a wasteful number, since it uses less digits than its factorization.

12865820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58501 (or 58499 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 12865820 is about 3586.8955936854. The cubic root of 12865820 is about 234.3216896825.

The spelling of 12865820 in words is "twelve million, eight hundred sixty-five thousand, eight hundred twenty".