775638761 has 2 divisors, whose sum is σ = 775638762. Its totient is φ = 775638760.

The previous prime is 775638751. The next prime is 775638763. The reversal of 775638761 is 167836577.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 606144400 + 169494361 = 24620^2 + 13019^2 .

It is a cyclic number.

It is not a de Polignac number, because 775638761 - 2¹⁸ = 775376617 is a prime.

Together with 775638763, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (775638763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 387819380 + 387819381.

It is an arithmetic number, because the mean of its divisors is an integer number (387819381).

Almost surely, 2^775638761 is an apocalyptic number.

It is an amenable number.

775638761 is a deficient number, since it is larger than the sum of its proper divisors (1).

775638761 is an equidigital number, since it uses as much as digits as its factorization.

775638761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1481760, while the sum is 50.

The square root of 775638761 is about 27850.2919374286. The cubic root of 775638761 is about 918.7975630829.

The spelling of 775638761 in words is "seven hundred seventy-five million, six hundred thirty-eight thousand, seven hundred sixty-one".