765777989 has 2 divisors, whose sum is σ = 765777990. Its totient is φ = 765777988.

The previous prime is 765777967. The next prime is 765777997. The reversal of 765777989 is 989777567.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 705327364 + 60450625 = 26558^2 + 7775^2 .

It is a cyclic number.

It is not a de Polignac number, because 765777989 - 2¹² = 765773893 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (765777959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 382888994 + 382888995.

It is an arithmetic number, because the mean of its divisors is an integer number (382888995).

Almost surely, 2^765777989 is an apocalyptic number.

It is an amenable number.

765777989 is a deficient number, since it is larger than the sum of its proper divisors (1).

765777989 is an equidigital number, since it uses as much as digits as its factorization.

765777989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46675440, while the sum is 65.

The square root of 765777989 is about 27672.6939237943. The cubic root of 765777989 is about 914.8873577083.

The spelling of 765777989 in words is "seven hundred sixty-five million, seven hundred seventy-seven thousand, nine hundred eighty-nine".