12812220 has 144 divisors (see below), whose sum is σ = 42456960. Its totient is φ = 3115008.

The previous prime is 12812197. The next prime is 12812227. The reversal of 12812220 is 2221821.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 12812193 and 12812202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12812227) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 162141 + ... + 162219.

It is an arithmetic number, because the mean of its divisors is an integer number (294840).

Almost surely, 2^12812220 is an apocalyptic number.

12812220 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 12812220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21228480).

12812220 is an abundant number, since it is smaller than the sum of its proper divisors (29644740).

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

12812220 is a wasteful number, since it uses less digits than its factorization.

12812220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 12812220 is about 3579.4161535088. The cubic root of 12812220 is about 233.9958359987.

The spelling of 12812220 in words is "twelve million, eight hundred twelve thousand, two hundred twenty".