667688333281 has 2 divisors, whose sum is σ = 667688333282. Its totient is φ = 667688333280.

The previous prime is 667688333189. The next prime is 667688333311. The reversal of 667688333281 is 182333886766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 648475878400 + 19212454881 = 805280^2 + 138609^2 .

It is a cyclic number.

It is not a de Polignac number, because 667688333281 - 2⁷ = 667688333153 is a prime.

It is a super-2 number, since 2×667688333281² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (667688333981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333844166640 + 333844166641.

It is an arithmetic number, because the mean of its divisors is an integer number (333844166641).

Almost surely, 2^667688333281 is an apocalyptic number.

It is an amenable number.

667688333281 is a deficient number, since it is larger than the sum of its proper divisors (1).

667688333281 is an equidigital number, since it uses as much as digits as its factorization.

667688333281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41803776, while the sum is 61.

The spelling of 667688333281 in words is "six hundred sixty-seven billion, six hundred eighty-eight million, three hundred thirty-three thousand, two hundred eighty-one".