67243021 has 2 divisors, whose sum is σ = 67243022. Its totient is φ = 67243020.

The previous prime is 67242979. The next prime is 67243027. The reversal of 67243021 is 12034276.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54922921 + 12320100 = 7411^2 + 3510^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67243021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67243027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33621510 + 33621511.

It is an arithmetic number, because the mean of its divisors is an integer number (33621511).

Almost surely, 2^67243021 is an apocalyptic number.

It is an amenable number.

67243021 is a deficient number, since it is larger than the sum of its proper divisors (1).

67243021 is an equidigital number, since it uses as much as digits as its factorization.

67243021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 67243021 is about 8200.1842052481. The cubic root of 67243021 is about 406.6452829241.

Adding to 67243021 its reverse (12034276), we get a palindrome (79277297).

The spelling of 67243021 in words is "sixty-seven million, two hundred forty-three thousand, twenty-one".