3128531 has 4 divisors (see below), whose sum is σ = 3575472. Its totient is φ = 2681592.

The previous prime is 3128501. The next prime is 3128533. The reversal of 3128531 is 1358213.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 3128531 - 2¹⁴ = 3112147 is a prime.

It is a super-2 number, since 2×3128531² = 19575412435922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3128497 and 3128506.

It is not an unprimeable number, because it can be changed into a prime (3128533) 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, 223460 + ... + 223473.

It is an arithmetic number, because the mean of its divisors is an integer number (893868).

Almost surely, 2^3128531 is an apocalyptic number.

3128531 is a deficient number, since it is larger than the sum of its proper divisors (446941).

3128531 is an equidigital number, since it uses as much as digits as its factorization.

3128531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446940.

The product of its digits is 720, while the sum is 23.

The square root of 3128531 is about 1768.7653886256. The cubic root of 3128531 is about 146.2559312860.

The spelling of 3128531 in words is "three million, one hundred twenty-eight thousand, five hundred thirty-one".