3128689 has 2 divisors, whose sum is σ = 3128690. Its totient is φ = 3128688.

The previous prime is 3128687. The next prime is 3128693. The reversal of 3128689 is 9868213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3122289 + 6400 = 1767^2 + 80^2 .

It is a cyclic number.

It is not a de Polignac number, because 3128689 - 2¹ = 3128687 is a prime.

Together with 3128687, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3128687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1564344 + 1564345.

It is an arithmetic number, because the mean of its divisors is an integer number (1564345).

Almost surely, 2^3128689 is an apocalyptic number.

It is an amenable number.

3128689 is a deficient number, since it is larger than the sum of its proper divisors (1).

3128689 is an equidigital number, since it uses as much as digits as its factorization.

3128689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 37.

The square root of 3128689 is about 1768.8100519841. The cubic root of 3128689 is about 146.2583933625.

It can be divided in two parts, 31286 and 89, that added together give a triangular number (31375 = T₂₅₀).

The spelling of 3128689 in words is "three million, one hundred twenty-eight thousand, six hundred eighty-nine".