12640365481 has 2 divisors, whose sum is σ = 12640365482. Its totient is φ = 12640365480.

The previous prime is 12640365473. The next prime is 12640365523. The reversal of 12640365481 is 18456304621.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7548829456 + 5091536025 = 86884^2 + 71355^2 .

It is a cyclic number.

It is not a de Polignac number, because 12640365481 - 2³ = 12640365473 is a prime.

It is a super-2 number, since 2×12640365481² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (12640365431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6320182740 + 6320182741.

It is an arithmetic number, because the mean of its divisors is an integer number (6320182741).

Almost surely, 2^12640365481 is an apocalyptic number.

It is an amenable number.

12640365481 is a deficient number, since it is larger than the sum of its proper divisors (1).

12640365481 is an equidigital number, since it uses as much as digits as its factorization.

12640365481 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 40.

The spelling of 12640365481 in words is "twelve billion, six hundred forty million, three hundred sixty-five thousand, four hundred eighty-one".