766668732821 has 2 divisors, whose sum is σ = 766668732822. Its totient is φ = 766668732820.

The previous prime is 766668732799. The next prime is 766668732827. The reversal of 766668732821 is 128237866667.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 581391000100 + 185277732721 = 762490^2 + 430439^2 .

It is a cyclic number.

It is not a de Polignac number, because 766668732821 - 2²² = 766664538517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (766668732827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 383334366410 + 383334366411.

It is an arithmetic number, because the mean of its divisors is an integer number (383334366411).

Almost surely, 2^766668732821 is an apocalyptic number.

It is an amenable number.

766668732821 is a deficient number, since it is larger than the sum of its proper divisors (1).

766668732821 is an equidigital number, since it uses as much as digits as its factorization.

766668732821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48771072, while the sum is 62.

The spelling of 766668732821 in words is "seven hundred sixty-six billion, six hundred sixty-eight million, seven hundred thirty-two thousand, eight hundred twenty-one".