3128717981 has 2 divisors, whose sum is σ = 3128717982. Its totient is φ = 3128717980.

The previous prime is 3128717971. The next prime is 3128718013. The reversal of 3128717981 is 1897178213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3128612356 + 105625 = 55934^2 + 325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3128717981 is a prime.

It is a super-2 number, since 2×3128717981² = 19577752409265432722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3128717971) 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 as a sum of consecutive naturals, namely, 1564358990 + 1564358991.

It is an arithmetic number, because the mean of its divisors is an integer number (1564358991).

Almost surely, 2^3128717981 is an apocalyptic number.

It is an amenable number.

3128717981 is a deficient number, since it is larger than the sum of its proper divisors (1).

3128717981 is an equidigital number, since it uses as much as digits as its factorization.

3128717981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344, while the sum is 47.

The square root of 3128717981 is about 55934.9441851871. The cubic root of 3128717981 is about 1462.5884495755.

The spelling of 3128717981 in words is "three billion, one hundred twenty-eight million, seven hundred seventeen thousand, nine hundred eighty-one".