667554749 has 2 divisors, whose sum is σ = 667554750. Its totient is φ = 667554748.

The previous prime is 667554739. The next prime is 667554751. The reversal of 667554749 is 947455766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 598780900 + 68773849 = 24470^2 + 8293^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667554749 is a prime.

Together with 667554751, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 667554749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667554739) 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, 333777374 + 333777375.

It is an arithmetic number, because the mean of its divisors is an integer number (333777375).

Almost surely, 2^667554749 is an apocalyptic number.

It is an amenable number.

667554749 is a deficient number, since it is larger than the sum of its proper divisors (1).

667554749 is an equidigital number, since it uses as much as digits as its factorization.

667554749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6350400, while the sum is 53.

The square root of 667554749 is about 25837.0808916178. The cubic root of 667554749 is about 873.9681983063.

The spelling of 667554749 in words is "six hundred sixty-seven million, five hundred fifty-four thousand, seven hundred forty-nine".