766775861 has 2 divisors, whose sum is σ = 766775862. Its totient is φ = 766775860.

The previous prime is 766775843. The next prime is 766775887. The reversal of 766775861 is 168577667.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 764799025 + 1976836 = 27655^2 + 1406^2 .

It is a cyclic number.

It is not a de Polignac number, because 766775861 - 2⁶ = 766775797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (766774861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 383387930 + 383387931.

It is an arithmetic number, because the mean of its divisors is an integer number (383387931).

Almost surely, 2^766775861 is an apocalyptic number.

It is an amenable number.

766775861 is a deficient number, since it is larger than the sum of its proper divisors (1).

766775861 is an equidigital number, since it uses as much as digits as its factorization.

766775861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2963520, while the sum is 53.

The square root of 766775861 is about 27690.7179574673. The cubic root of 766775861 is about 915.2845764983.

The spelling of 766775861 in words is "seven hundred sixty-six million, seven hundred seventy-five thousand, eight hundred sixty-one".