12756121249 has 9 divisors (see below), whose sum is σ = 13007447859. Its totient is φ = 12509566680.

The previous prime is 12756121247. The next prime is 12756121291. The reversal of 12756121249 is 94212165721.

The square root of 12756121249 is 112943.

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

It can be written as a sum of positive squares in only one way, i.e., 9195851025 + 3560270224 = 95895^2 + 59668^2 .

It is not a de Polignac number, because 12756121249 - 2¹ = 12756121247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12756121247) 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, 5984914 + ... + 5987044.

Almost surely, 2^12756121249 is an apocalyptic number.

12756121249 is the 112943-rd square number.

12756121249 is the 56472-nd centered octagonal number.

It is an amenable number.

12756121249 is a deficient number, since it is larger than the sum of its proper divisors (251326610).

12756121249 is an frugal number, since it uses more digits than its factorization.

12756121249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4368 (or 2184 counting only the distinct ones).

The product of its digits is 60480, while the sum is 40.

The spelling of 12756121249 in words is "twelve billion, seven hundred fifty-six million, one hundred twenty-one thousand, two hundred forty-nine".