1312128189 has 6 divisors (see below), whose sum is σ = 1895296286. Its totient is φ = 874752120.

The previous prime is 1312128179. The next prime is 1312128197. The reversal of 1312128189 is 9818212131.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 831860964 + 480267225 = 28842^2 + 21915^2 .

It is not a de Polignac number, because 1312128189 - 2¹³ = 1312119997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312128109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 72896002 + ... + 72896019.

Almost surely, 2^1312128189 is an apocalyptic number.

It is an amenable number.

1312128189 is a deficient number, since it is larger than the sum of its proper divisors (583168097).

1312128189 is a wasteful number, since it uses less digits than its factorization.

1312128189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145792027 (or 145792024 counting only the distinct ones).

The product of its digits is 6912, while the sum is 36.

The square root of 1312128189 is about 36223.3100226912. The cubic root of 1312128189 is about 1094.7763876909.

The spelling of 1312128189 in words is "one billion, three hundred twelve million, one hundred twenty-eight thousand, one hundred eighty-nine".