775128678917 has 2 divisors, whose sum is σ = 775128678918. Its totient is φ = 775128678916.

The previous prime is 775128678833. The next prime is 775128678943. The reversal of 775128678917 is 719876821577.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 765640750081 + 9487928836 = 875009^2 + 97406^2 .

It is a cyclic number.

It is not a de Polignac number, because 775128678917 - 2⁸ = 775128678661 is a prime.

It is a super-2 number, since 2×775128678917² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (775128678967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 387564339458 + 387564339459.

It is an arithmetic number, because the mean of its divisors is an integer number (387564339459).

Almost surely, 2^775128678917 is an apocalyptic number.

It is an amenable number.

775128678917 is a deficient number, since it is larger than the sum of its proper divisors (1).

775128678917 is an equidigital number, since it uses as much as digits as its factorization.

775128678917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82978560, while the sum is 68.

The spelling of 775128678917 in words is "seven hundred seventy-five billion, one hundred twenty-eight million, six hundred seventy-eight thousand, nine hundred seventeen".