667073706781 has 2 divisors, whose sum is σ = 667073706782. Its totient is φ = 667073706780.

The previous prime is 667073706749. The next prime is 667073706799. The reversal of 667073706781 is 187607370766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 548734266756 + 118339440025 = 740766^2 + 344005^2 .

It is a cyclic number.

It is not a de Polignac number, because 667073706781 - 2⁵ = 667073706749 is a prime.

It is a super-2 number, since 2×667073706781² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667073706701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333536853390 + 333536853391.

It is an arithmetic number, because the mean of its divisors is an integer number (333536853391).

Almost surely, 2^667073706781 is an apocalyptic number.

It is an amenable number.

667073706781 is a deficient number, since it is larger than the sum of its proper divisors (1).

667073706781 is an equidigital number, since it uses as much as digits as its factorization.

667073706781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12446784, while the sum is 58.

The spelling of 667073706781 in words is "six hundred sixty-seven billion, seventy-three million, seven hundred six thousand, seven hundred eighty-one".