12127789649 has 4 divisors (see below), whose sum is σ = 12133876836. Its totient is φ = 12121702464.

The previous prime is 12127789643. The next prime is 12127789679. The reversal of 12127789649 is 94698772121.

It is a happy number.

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 9924144400 + 2203645249 = 99620^2 + 46943^2 .

It is a cyclic number.

It is not a de Polignac number, because 12127789649 - 2⁴ = 12127789633 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12127789594 and 12127789603.

It is not an unprimeable number, because it can be changed into a prime (12127789643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3040604 + ... + 3044589.

It is an arithmetic number, because the mean of its divisors is an integer number (3033469209).

Almost surely, 2^12127789649 is an apocalyptic number.

It is an amenable number.

12127789649 is a deficient number, since it is larger than the sum of its proper divisors (6087187).

12127789649 is an equidigital number, since it uses as much as digits as its factorization.

12127789649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6087186.

The product of its digits is 3048192, while the sum is 56.

The spelling of 12127789649 in words is "twelve billion, one hundred twenty-seven million, seven hundred eighty-nine thousand, six hundred forty-nine".