12811520 has 36 divisors (see below), whose sum is σ = 30690660. Its totient is φ = 5124096.

The previous prime is 12811511. The next prime is 12811541. The reversal of 12811520 is 2511821.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 9935104 + 2876416 = 3152^2 + 1696^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 12811492 and 12811501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3725 + ... + 6284.

Almost surely, 2^12811520 is an apocalyptic number.

12811520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12811520 is an abundant number, since it is smaller than the sum of its proper divisors (17879140).

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

12811520 is an equidigital number, since it uses as much as digits as its factorization.

12811520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10030 (or 10016 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 20.

The square root of 12811520 is about 3579.3183708634. The cubic root of 12811520 is about 233.9915744403.

It can be divided in two parts, 12811 and 520, that added together give a palindrome (13331).

The spelling of 12811520 in words is "twelve million, eight hundred eleven thousand, five hundred twenty".