765500521 has 2 divisors, whose sum is σ = 765500522. Its totient is φ = 765500520.

The previous prime is 765500503. The next prime is 765500551. The reversal of 765500521 is 125005567.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 751362921 + 14137600 = 27411^2 + 3760^2 .

It is an emirp because it is prime and its reverse (125005567) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 765500521 - 2⁹ = 765500009 is a prime.

It is not a weakly prime, because it can be changed into another prime (765500551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 382750260 + 382750261.

It is an arithmetic number, because the mean of its divisors is an integer number (382750261).

Almost surely, 2^765500521 is an apocalyptic number.

It is an amenable number.

765500521 is a deficient number, since it is larger than the sum of its proper divisors (1).

765500521 is an equidigital number, since it uses as much as digits as its factorization.

765500521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 765500521 is about 27667.6800798332. The cubic root of 765500521 is about 914.7768458563.

The spelling of 765500521 in words is "seven hundred sixty-five million, five hundred thousand, five hundred twenty-one".