12871981 has 4 divisors (see below), whose sum is σ = 13016700. Its totient is φ = 12727264.

The previous prime is 12871933. The next prime is 12872003. The reversal of 12871981 is 18917821.

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 7650756 + 5221225 = 2766^2 + 2285^2 .

It is a cyclic number.

It is not a de Polignac number, because 12871981 - 2¹¹ = 12869933 is a prime.

It is a super-2 number, since 2×12871981² = 331375789728722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12871981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12871081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72226 + ... + 72403.

It is an arithmetic number, because the mean of its divisors is an integer number (3254175).

Almost surely, 2^12871981 is an apocalyptic number.

It is an amenable number.

12871981 is a deficient number, since it is larger than the sum of its proper divisors (144719).

12871981 is an equidigital number, since it uses as much as digits as its factorization.

12871981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144718.

The product of its digits is 8064, while the sum is 37.

The square root of 12871981 is about 3587.7543115436. The cubic root of 12871981 is about 234.3590865877.

The spelling of 12871981 in words is "twelve million, eight hundred seventy-one thousand, nine hundred eighty-one".