12877991645 has 4 divisors (see below), whose sum is σ = 15453589980. Its totient is φ = 10302393312.

The previous prime is 12877991603. The next prime is 12877991647. The reversal of 12877991645 is 54619977821.

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 9661513849 + 3216477796 = 98293^2 + 56714^2 .

It is a cyclic number.

It is not a de Polignac number, because 12877991645 - 2²⁰ = 12876943069 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12877991647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1287799160 + ... + 1287799169.

It is an arithmetic number, because the mean of its divisors is an integer number (3863397495).

Almost surely, 2^12877991645 is an apocalyptic number.

It is an amenable number.

12877991645 is a deficient number, since it is larger than the sum of its proper divisors (2575598335).

12877991645 is an equidigital number, since it uses as much as digits as its factorization.

12877991645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2575598334.

The product of its digits is 7620480, while the sum is 59.

The spelling of 12877991645 in words is "twelve billion, eight hundred seventy-seven million, nine hundred ninety-one thousand, six hundred forty-five".