2131243021 has 2 divisors, whose sum is σ = 2131243022. Its totient is φ = 2131243020.

The previous prime is 2131243019. The next prime is 2131243067. The reversal of 2131243021 is 1203421312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1898344900 + 232898121 = 43570^2 + 15261^2 .

It is a cyclic number.

It is not a de Polignac number, because 2131243021 - 2¹ = 2131243019 is a prime.

It is a super-2 number, since 2×2131243021² = 9084393629122412882, which contains 22 as substring.

Together with 2131243019, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 2131243021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2131243421) 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, 1065621510 + 1065621511.

It is an arithmetic number, because the mean of its divisors is an integer number (1065621511).

Almost surely, 2^2131243021 is an apocalyptic number.

It is an amenable number.

2131243021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2131243021 is an equidigital number, since it uses as much as digits as its factorization.

2131243021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 2131243021 is about 46165.3876946788. The cubic root of 2131243021 is about 1286.8985890813.

Adding to 2131243021 its reverse (1203421312), we get a palindrome (3334664333).

The spelling of 2131243021 in words is "two billion, one hundred thirty-one million, two hundred forty-three thousand, twenty-one".