67279721 has 2 divisors, whose sum is σ = 67279722. Its totient is φ = 67279720.

The previous prime is 67279697. The next prime is 67279733. The reversal of 67279721 is 12797276.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64000000 + 3279721 = 8000^2 + 1811^2 .

It is a cyclic number.

It is not a de Polignac number, because 67279721 - 2⁶ = 67279657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (67279621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33639860 + 33639861.

It is an arithmetic number, because the mean of its divisors is an integer number (33639861).

Almost surely, 2^67279721 is an apocalyptic number.

It is an amenable number.

67279721 is a deficient number, since it is larger than the sum of its proper divisors (1).

67279721 is an equidigital number, since it uses as much as digits as its factorization.

67279721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 74088, while the sum is 41.

The square root of 67279721 is about 8202.4216546091. The cubic root of 67279721 is about 406.7192492997.

It can be divided in two parts, 6 and 7279721, that added together give a palindrome (7279727).

The spelling of 67279721 in words is "sixty-seven million, two hundred seventy-nine thousand, seven hundred twenty-one".