765255561 has 16 divisors (see below), whose sum is σ = 1234698624. Its totient is φ = 411565824.

The previous prime is 765255521. The next prime is 765255587. The reversal of 765255561 is 165552567.

It is a happy number.

It is not a de Polignac number, because 765255561 - 2¹⁰ = 765254537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (765255521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1071430 + ... + 1072143.

It is an arithmetic number, because the mean of its divisors is an integer number (77168664).

Almost surely, 2^765255561 is an apocalyptic number.

It is an amenable number.

765255561 is a deficient number, since it is larger than the sum of its proper divisors (469443063).

765255561 is a wasteful number, since it uses less digits than its factorization.

765255561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2143600.

The product of its digits is 315000, while the sum is 42.

The square root of 765255561 is about 27663.2528998309. The cubic root of 765255561 is about 914.6792593159.

The spelling of 765255561 in words is "seven hundred sixty-five million, two hundred fifty-five thousand, five hundred sixty-one".