12815820 has 96 divisors (see below), whose sum is σ = 40501440. Its totient is φ = 3405888.

The previous prime is 12815813. The next prime is 12815833. The reversal of 12815820 is 2851821.

12815820 is a `hidden beast` number, since 1 + 2 + 81 + 582 + 0 = 666.

12815820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43594 + ... + 43886.

It is an arithmetic number, because the mean of its divisors is an integer number (421890).

Almost surely, 2^12815820 is an apocalyptic number.

12815820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12815820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20250720).

12815820 is an abundant number, since it is smaller than the sum of its proper divisors (27685620).

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

12815820 is an equidigital number, since it uses as much as digits as its factorization.

12815820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 303 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 12815820 is about 3579.9189934969. The cubic root of 12815820 is about 234.0177501328.

The spelling of 12815820 in words is "twelve million, eight hundred fifteen thousand, eight hundred twenty".