766661155769 has 2 divisors, whose sum is σ = 766661155770. Its totient is φ = 766661155768.

The previous prime is 766661155691. The next prime is 766661155781. The reversal of 766661155769 is 967551166667.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 676728343225 + 89932812544 = 822635^2 + 299888^2 .

It is a cyclic number.

It is not a de Polignac number, because 766661155769 - 2³⁶ = 697941679033 is a prime.

It is a super-2 number, since 2×766661155769² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (766661155789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 383330577884 + 383330577885.

It is an arithmetic number, because the mean of its divisors is an integer number (383330577885).

Almost surely, 2^766661155769 is an apocalyptic number.

It is an amenable number.

766661155769 is a deficient number, since it is larger than the sum of its proper divisors (1).

766661155769 is an equidigital number, since it uses as much as digits as its factorization.

766661155769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 85730400, while the sum is 65.

The spelling of 766661155769 in words is "seven hundred sixty-six billion, six hundred sixty-one million, one hundred fifty-five thousand, seven hundred sixty-nine".