3128729 has 2 divisors, whose sum is σ = 3128730. Its totient is φ = 3128728.

The previous prime is 3128701. The next prime is 3128747. The reversal of 3128729 is 9278213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2968729 + 160000 = 1723^2 + 400^2 .

It is a cyclic number.

It is not a de Polignac number, because 3128729 - 2¹² = 3124633 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 3128695 and 3128704.

It is not a weakly prime, because it can be changed into another prime (3128779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1564364 + 1564365.

It is an arithmetic number, because the mean of its divisors is an integer number (1564365).

Almost surely, 2^3128729 is an apocalyptic number.

It is an amenable number.

3128729 is a deficient number, since it is larger than the sum of its proper divisors (1).

3128729 is an equidigital number, since it uses as much as digits as its factorization.

3128729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 32.

The square root of 3128729 is about 1768.8213589846. The cubic root of 3128729 is about 146.2590166599.

The spelling of 3128729 in words is "three million, one hundred twenty-eight thousand, seven hundred twenty-nine".