67317721 has 2 divisors, whose sum is σ = 67317722. Its totient is φ = 67317720.

The previous prime is 67317713. The next prime is 67317737. The reversal of 67317721 is 12771376.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63361600 + 3956121 = 7960^2 + 1989^2 .

It is a cyclic number.

It is not a de Polignac number, because 67317721 - 2³ = 67317713 is a prime.

It is not a weakly prime, because it can be changed into another prime (67317421) 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, 33658860 + 33658861.

It is an arithmetic number, because the mean of its divisors is an integer number (33658861).

Almost surely, 2^67317721 is an apocalyptic number.

It is an amenable number.

67317721 is a deficient number, since it is larger than the sum of its proper divisors (1).

67317721 is an equidigital number, since it uses as much as digits as its factorization.

67317721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12348, while the sum is 34.

The square root of 67317721 is about 8204.7377167098. The cubic root of 67317721 is about 406.7958073987.

The spelling of 67317721 in words is "sixty-seven million, three hundred seventeen thousand, seven hundred twenty-one".