67782721 has 2 divisors, whose sum is σ = 67782722. Its totient is φ = 67782720.

The previous prime is 67782719. The next prime is 67782733. The reversal of 67782721 is 12728776.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44742721 + 23040000 = 6689^2 + 4800^2 .

It is a cyclic number.

It is not a de Polignac number, because 67782721 - 2¹ = 67782719 is a prime.

Together with 67782719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (67782751) 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, 33891360 + 33891361.

It is an arithmetic number, because the mean of its divisors is an integer number (33891361).

Almost surely, 2^67782721 is an apocalyptic number.

It is an amenable number.

67782721 is a deficient number, since it is larger than the sum of its proper divisors (1).

67782721 is an equidigital number, since it uses as much as digits as its factorization.

67782721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 65856, while the sum is 40.

The square root of 67782721 is about 8233.0262358382. The cubic root of 67782721 is about 407.7303120518.

The spelling of 67782721 in words is "sixty-seven million, seven hundred eighty-two thousand, seven hundred twenty-one".