12881021 has 4 divisors (see below), whose sum is σ = 12937500. Its totient is φ = 12824544.

The previous prime is 12880999. The next prime is 12881023. The reversal of 12881021 is 12018821.

It is a happy number.

12881021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11978521 + 902500 = 3461^2 + 950^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12881021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12881023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27896 + ... + 28353.

It is an arithmetic number, because the mean of its divisors is an integer number (3234375).

Almost surely, 2^12881021 is an apocalyptic number.

It is an amenable number.

12881021 is a deficient number, since it is larger than the sum of its proper divisors (56479).

12881021 is an equidigital number, since it uses as much as digits as its factorization.

12881021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56478.

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 12881021 is about 3589.0139314302. The cubic root of 12881021 is about 234.4139372583.

Adding to 12881021 its reverse (12018821), we get a palindrome (24899842).

The spelling of 12881021 in words is "twelve million, eight hundred eighty-one thousand, twenty-one".