12686643225 has 45 divisors (see below), whose sum is σ = 23509441263. Its totient is φ = 6763506480.

The previous prime is 12686643223. The next prime is 12686643251. The reversal of 12686643225 is 52234668621.

The square root of 12686643225 is 112635.

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

12686643225 is a `hidden beast` number, since 1 + 268 + 6 + 64 + 322 + 5 = 666.

It can be written as a sum of positive squares in only one way, i.e., 4567191561 + 8119451664 = 67581^2 + 90108^2 .

It is a tau number, because it is divible by the number of its divisors (45).

It is not a de Polignac number, because 12686643225 - 2¹ = 12686643223 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (12686643223) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 5067324 + ... + 5069826.

Almost surely, 2^12686643225 is an apocalyptic number.

12686643225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

12686643225 is the 112635-th square number.

12686643225 is the 56318-th centered octagonal number.

It is an amenable number.

12686643225 is a deficient number, since it is larger than the sum of its proper divisors (10822798038).

12686643225 is an frugal number, since it uses more digits than its factorization.

12686643225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5028 (or 2511 counting only the distinct ones).

The product of its digits is 829440, while the sum is 45.

The spelling of 12686643225 in words is "twelve billion, six hundred eighty-six million, six hundred forty-three thousand, two hundred twenty-five".