766668733681 has 2 divisors, whose sum is σ = 766668733682. Its totient is φ = 766668733680.

The previous prime is 766668733673. The next prime is 766668733729. The reversal of 766668733681 is 186337866667.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 663884373681 + 102784360000 = 814791^2 + 320600^2 .

It is a cyclic number.

It is not a de Polignac number, because 766668733681 - 2³ = 766668733673 is a prime.

It is a super-2 number, since 2×766668733681² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (766668733631) 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, 383334366840 + 383334366841.

It is an arithmetic number, because the mean of its divisors is an integer number (383334366841).

Almost surely, 2^766668733681 is an apocalyptic number.

It is an amenable number.

766668733681 is a deficient number, since it is larger than the sum of its proper divisors (1).

766668733681 is an equidigital number, since it uses as much as digits as its factorization.

766668733681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 219469824, while the sum is 67.

The spelling of 766668733681 in words is "seven hundred sixty-six billion, six hundred sixty-eight million, seven hundred thirty-three thousand, six hundred eighty-one".