12639481 has 2 divisors, whose sum is σ = 12639482. Its totient is φ = 12639480.

The previous prime is 12639479. The next prime is 12639527. The reversal of 12639481 is 18493621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10949481 + 1690000 = 3309^2 + 1300^2 .

It is an emirp because it is prime and its reverse (18493621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12639481 - 2¹ = 12639479 is a prime.

It is a super-2 number, since 2×12639481² = 319512959898722, which contains 22 as substring.

Together with 12639479, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (12639461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6319740 + 6319741.

It is an arithmetic number, because the mean of its divisors is an integer number (6319741).

Almost surely, 2^12639481 is an apocalyptic number.

It is an amenable number.

12639481 is a deficient number, since it is larger than the sum of its proper divisors (1).

12639481 is an equidigital number, since it uses as much as digits as its factorization.

12639481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 34.

The square root of 12639481 is about 3555.2047760994. The cubic root of 12639481 is about 232.9394686404.

The spelling of 12639481 in words is "twelve million, six hundred thirty-nine thousand, four hundred eighty-one".