12687981 has 8 divisors (see below), whose sum is σ = 17041344. Its totient is φ = 8396640.

The previous prime is 12687977. The next prime is 12687989. The reversal of 12687981 is 18978621.

12687981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12687981 - 2² = 12687977 is a prime.

It is a super-2 number, since 2×12687981² = 321969723712722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12687989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15025 + ... + 15846.

It is an arithmetic number, because the mean of its divisors is an integer number (2130168).

Almost surely, 2^12687981 is an apocalyptic number.

It is an amenable number.

12687981 is a deficient number, since it is larger than the sum of its proper divisors (4353363).

12687981 is a wasteful number, since it uses less digits than its factorization.

12687981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31011.

The product of its digits is 48384, while the sum is 42.

The square root of 12687981 is about 3562.0192307173. The cubic root of 12687981 is about 233.2370321422.

The spelling of 12687981 in words is "twelve million, six hundred eighty-seven thousand, nine hundred eighty-one".