667644953 has 2 divisors, whose sum is σ = 667644954. Its totient is φ = 667644952.

The previous prime is 667644941. The next prime is 667644959. The reversal of 667644953 is 359446766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 510217744 + 157427209 = 22588^2 + 12547^2 .

It is a cyclic number.

It is not a de Polignac number, because 667644953 - 2⁴ = 667644937 is a prime.

It is not a weakly prime, because it can be changed into another prime (667644959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333822476 + 333822477.

It is an arithmetic number, because the mean of its divisors is an integer number (333822477).

Almost surely, 2^667644953 is an apocalyptic number.

It is an amenable number.

667644953 is a deficient number, since it is larger than the sum of its proper divisors (1).

667644953 is an equidigital number, since it uses as much as digits as its factorization.

667644953 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3265920, while the sum is 50.

The square root of 667644953 is about 25838.8264632897. The cubic root of 667644953 is about 874.0075618076.

It can be divided in two parts, 66764 and 4953, that added together give a palindrome (71717).

The spelling of 667644953 in words is "six hundred sixty-seven million, six hundred forty-four thousand, nine hundred fifty-three".