12913981 has 2 divisors, whose sum is σ = 12913982. Its totient is φ = 12913980.

The previous prime is 12913969. The next prime is 12913991. The reversal of 12913981 is 18931921.

12913981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8608356 + 4305625 = 2934^2 + 2075^2 .

It is a cyclic number.

It is not a de Polignac number, because 12913981 - 2⁷ = 12913853 is a prime.

It is a super-2 number, since 2×12913981² = 333541810536722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12913921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6456990 + 6456991.

It is an arithmetic number, because the mean of its divisors is an integer number (6456991).

Almost surely, 2^12913981 is an apocalyptic number.

It is an amenable number.

12913981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12913981 is an equidigital number, since it uses as much as digits as its factorization.

12913981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 34.

The square root of 12913981 is about 3593.6027882892. The cubic root of 12913981 is about 234.6137066894.

The spelling of 12913981 in words is "twelve million, nine hundred thirteen thousand, nine hundred eighty-one".