12866555820 has 48 divisors (see below), whose sum is σ = 36156462048. Its totient is φ = 3418690560.

The previous prime is 12866555813. The next prime is 12866555839. The reversal of 12866555820 is 2855566821.

It is a self number, because there is not a number n which added to its sum of digits gives 12866555820.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 370461 + ... + 403700.

It is an arithmetic number, because the mean of its divisors is an integer number (753259626).

Almost surely, 2^12866555820 is an apocalyptic number.

12866555820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12866555820 is an abundant number, since it is smaller than the sum of its proper divisors (23289906228).

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

12866555820 is a wasteful number, since it uses less digits than its factorization.

12866555820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 774450 (or 774448 counting only the distinct ones).

The product of its (nonzero) digits is 1152000, while the sum is 48.

The spelling of 12866555820 in words is "twelve billion, eight hundred sixty-six million, five hundred fifty-five thousand, eight hundred twenty".