3128981 has 4 divisors (see below), whose sum is σ = 3201792. Its totient is φ = 3056172.

The previous prime is 3128941. The next prime is 3128987. The reversal of 3128981 is 1898213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1898213 = 23 ⋅82531.

It is a cyclic number.

It is not a de Polignac number, because 3128981 - 2¹⁸ = 2866837 is a prime.

It is a super-2 number, since 2×3128981² = 19581044196722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3128987) 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, 36341 + ... + 36426.

It is an arithmetic number, because the mean of its divisors is an integer number (800448).

Almost surely, 2^3128981 is an apocalyptic number.

It is an amenable number.

3128981 is a deficient number, since it is larger than the sum of its proper divisors (72811).

3128981 is an equidigital number, since it uses as much as digits as its factorization.

3128981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72810.

The product of its digits is 3456, while the sum is 32.

The square root of 3128981 is about 1768.8925914255. The cubic root of 3128981 is about 146.2629433111.

The spelling of 3128981 in words is "three million, one hundred twenty-eight thousand, nine hundred eighty-one".