667222729 has 2 divisors, whose sum is σ = 667222730. Its totient is φ = 667222728.

The previous prime is 667222727. The next prime is 667222741. The reversal of 667222729 is 927222766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 342250000 + 324972729 = 18500^2 + 18027^2 .

It is a cyclic number.

It is not a de Polignac number, because 667222729 - 2¹ = 667222727 is a prime.

Together with 667222727, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (667222727) 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, 333611364 + 333611365.

It is an arithmetic number, because the mean of its divisors is an integer number (333611365).

Almost surely, 2^667222729 is an apocalyptic number.

It is an amenable number.

667222729 is a deficient number, since it is larger than the sum of its proper divisors (1).

667222729 is an equidigital number, since it uses as much as digits as its factorization.

667222729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 254016, while the sum is 43.

The square root of 667222729 is about 25830.6548310336. The cubic root of 667222729 is about 873.8232798344.

The spelling of 667222729 in words is "six hundred sixty-seven million, two hundred twenty-two thousand, seven hundred twenty-nine".