12964481581 has 4 divisors (see below), whose sum is σ = 13411532700. Its totient is φ = 12517430464.

The previous prime is 12964481549. The next prime is 12964481617. The reversal of 12964481581 is 18518446921.

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 8221955625 + 4742525956 = 90675^2 + 68866^2 .

It is a cyclic number.

It is not a de Polignac number, because 12964481581 - 2⁵ = 12964481549 is a prime.

It is a super-2 number, since 2×12964481581² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12964481521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223525516 + ... + 223525573.

It is an arithmetic number, because the mean of its divisors is an integer number (3352883175).

Almost surely, 2^12964481581 is an apocalyptic number.

It is an amenable number.

12964481581 is a deficient number, since it is larger than the sum of its proper divisors (447051119).

12964481581 is an equidigital number, since it uses as much as digits as its factorization.

12964481581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447051118.

The product of its digits is 552960, while the sum is 49.

The spelling of 12964481581 in words is "twelve billion, nine hundred sixty-four million, four hundred eighty-one thousand, five hundred eighty-one".