865618513 has 2 divisors, whose sum is σ = 865618514. Its totient is φ = 865618512.

The previous prime is 865618463. The next prime is 865618519. The reversal of 865618513 is 315816568.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 545315904 + 320302609 = 23352^2 + 17897^2 .

It is a cyclic number.

It is not a de Polignac number, because 865618513 - 2²⁵ = 832064081 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 865618513.

It is not a weakly prime, because it can be changed into another prime (865618519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432809256 + 432809257.

It is an arithmetic number, because the mean of its divisors is an integer number (432809257).

Almost surely, 2^865618513 is an apocalyptic number.

It is an amenable number.

865618513 is a deficient number, since it is larger than the sum of its proper divisors (1).

865618513 is an equidigital number, since it uses as much as digits as its factorization.

865618513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 172800, while the sum is 43.

The square root of 865618513 is about 29421.3954971548. The cubic root of 865618513 is about 953.0349891930.

The spelling of 865618513 in words is "eight hundred sixty-five million, six hundred eighteen thousand, five hundred thirteen".