12511988449 has 3 divisors (see below), whose sum is σ = 12512100307. Its totient is φ = 12511876592.

The previous prime is 12511988443. The next prime is 12511988453. The reversal of 12511988449 is 94488911521.

The square root of 12511988449 is 111857.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 94488911521 = 43 ⋅2197416547.

It can be written as a sum of positive squares in only one way, i.e., 1226750625 + 11285237824 = 35025^2 + 106232^2 .

It is not a de Polignac number, because 12511988449 - 2⁹ = 12511987937 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12511988396 and 12511988405.

It is not an unprimeable number, because it can be changed into a prime (12511988443) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 55929 + ... + 167785.

Almost surely, 2^12511988449 is an apocalyptic number.

12511988449 is the 111857-th square number.

12511988449 is the 55929-th centered octagonal number.

It is an amenable number.

12511988449 is a deficient number, since it is larger than the sum of its proper divisors (111858).

12511988449 is an frugal number, since it uses more digits than its factorization.

12511988449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223714 (or 111857 counting only the distinct ones).

The product of its digits is 829440, while the sum is 52.

The spelling of 12511988449 in words is "twelve billion, five hundred eleven million, nine hundred eighty-eight thousand, four hundred forty-nine".