667661249 has 2 divisors, whose sum is σ = 667661250. Its totient is φ = 667661248.

The previous prime is 667661233. The next prime is 667661327. The reversal of 667661249 is 942166766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 368371249 + 299290000 = 19193^2 + 17300^2 .

It is a cyclic number.

It is not a de Polignac number, because 667661249 - 2⁴ = 667661233 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (667661749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333830624 + 333830625.

It is an arithmetic number, because the mean of its divisors is an integer number (333830625).

Almost surely, 2^667661249 is an apocalyptic number.

It is an amenable number.

667661249 is a deficient number, since it is larger than the sum of its proper divisors (1).

667661249 is an equidigital number, since it uses as much as digits as its factorization.

667661249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 47.

The square root of 667661249 is about 25839.1418007642. The cubic root of 667661249 is about 874.0146727285.

The spelling of 667661249 in words is "six hundred sixty-seven million, six hundred sixty-one thousand, two hundred forty-nine".