12644777601 has 9 divisors (see below), whose sum is σ = 18265166049. Its totient is φ = 8429626836.

The previous prime is 12644777591. The next prime is 12644777611. The reversal of 12644777601 is 10677744621.

The square root of 12644777601 is 112449.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (12644777591) and next prime (12644777611).

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 12644777601 - 2¹⁹ = 12644253313 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12644777611) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 318606 + ... + 356088.

Almost surely, 2^12644777601 is an apocalyptic number.

12644777601 is the 112449-th square number.

12644777601 is the 56225-th centered octagonal number.

It is an amenable number.

12644777601 is a deficient number, since it is larger than the sum of its proper divisors (5620388448).

12644777601 is an frugal number, since it uses more digits than its factorization.

12644777601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74972 (or 37486 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 45.

The spelling of 12644777601 in words is "twelve billion, six hundred forty-four million, seven hundred seventy-seven thousand, six hundred one".