12820566 has 32 divisors (see below), whose sum is σ = 28574208. Its totient is φ = 3801440.

The previous prime is 12820559. The next prime is 12820583. The reversal of 12820566 is 66502821.

It is a congruent number.

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, 1036 + ... + 5168.

It is an arithmetic number, because the mean of its divisors is an integer number (892944).

Almost surely, 2^12820566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12820566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14287104).

12820566 is an abundant number, since it is smaller than the sum of its proper divisors (15753642).

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

12820566 is a wasteful number, since it uses less digits than its factorization.

12820566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4196.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 12820566 is about 3580.5817963007. The cubic root of 12820566 is about 234.0466339959.

It can be divided in two parts, 128205 and 66, that added together give a triangular number (128271 = T₅₀₆).

The spelling of 12820566 in words is "twelve million, eight hundred twenty thousand, five hundred sixty-six".