3131021 has 2 divisors, whose sum is σ = 3131022. Its totient is φ = 3131020.

The previous prime is 3131017. The next prime is 3131027. The reversal of 3131021 is 1201313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2758921 + 372100 = 1661^2 + 610^2 .

It is a cyclic number.

It is not a de Polignac number, because 3131021 - 2² = 3131017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 3130993 and 3131011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3131027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1565510 + 1565511.

It is an arithmetic number, because the mean of its divisors is an integer number (1565511).

Almost surely, 2^3131021 is an apocalyptic number.

It is an amenable number.

3131021 is a deficient number, since it is larger than the sum of its proper divisors (1).

3131021 is an equidigital number, since it uses as much as digits as its factorization.

3131021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 11.

The square root of 3131021 is about 1769.4691294284. The cubic root of 3131021 is about 146.2947227289.

Adding to 3131021 its reverse (1201313), we get a palindrome (4332334).

The spelling of 3131021 in words is "three million, one hundred thirty-one thousand, twenty-one".