12788721 has 24 divisors (see below), whose sum is σ = 20367360. Its totient is φ = 7668000.

The previous prime is 12788719. The next prime is 12788801.

It is a happy number.

12788721 is nontrivially palindromic in base 10.

12788721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12788721 - 2¹ = 12788719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12788021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9360 + ... + 10638.

It is an arithmetic number, because the mean of its divisors is an integer number (848640).

Almost surely, 2^12788721 is an apocalyptic number.

12788721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12788721 is a deficient number, since it is larger than the sum of its proper divisors (7578639).

12788721 is a wasteful number, since it uses less digits than its factorization.

12788721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1397 (or 1394 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 12788721 is about 3576.1321284315. The cubic root of 12788721 is about 233.8526905407.

It can be divided in two parts, 1278 and 8721, that added together give a palindrome (9999).

The spelling of 12788721 in words is "twelve million, seven hundred eighty-eight thousand, seven hundred twenty-one".