766661155779 has 4 divisors (see below), whose sum is σ = 1022214874376. Its totient is φ = 511107437184.

The previous prime is 766661155769. The next prime is 766661155781. The reversal of 766661155779 is 977551166667.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-766661155779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (766661155769) 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 in 3 ways as a sum of consecutive naturals, for example, 127776859294 + ... + 127776859299.

It is an arithmetic number, because the mean of its divisors is an integer number (255553718594).

Almost surely, 2^766661155779 is an apocalyptic number.

766661155779 is a deficient number, since it is larger than the sum of its proper divisors (255553718597).

766661155779 is a wasteful number, since it uses less digits than its factorization.

766661155779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255553718596.

The product of its digits is 100018800, while the sum is 66.

The spelling of 766661155779 in words is "seven hundred sixty-six billion, six hundred sixty-one million, one hundred fifty-five thousand, seven hundred seventy-nine".