667644937 has 2 divisors, whose sum is σ = 667644938. Its totient is φ = 667644936.

The previous prime is 667644919. The next prime is 667644941. The reversal of 667644937 is 739446766.

667644937 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 493906176 + 173738761 = 22224^2 + 13181^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667644937 is a prime.

It is not a weakly prime, because it can be changed into another prime (667644997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333822468 + 333822469.

It is an arithmetic number, because the mean of its divisors is an integer number (333822469).

Almost surely, 2^667644937 is an apocalyptic number.

It is an amenable number.

667644937 is a deficient number, since it is larger than the sum of its proper divisors (1).

667644937 is an equidigital number, since it uses as much as digits as its factorization.

667644937 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4572288, while the sum is 52.

The square root of 667644937 is about 25838.8261536781. The cubic root of 667644937 is about 874.0075548258.

The spelling of 667644937 in words is "six hundred sixty-seven million, six hundred forty-four thousand, nine hundred thirty-seven".