865728551 has 2 divisors, whose sum is σ = 865728552. Its totient is φ = 865728550.

The previous prime is 865728529. The next prime is 865728583. The reversal of 865728551 is 155827568.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-865728551 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 865728496 and 865728505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (865728511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432864275 + 432864276.

It is an arithmetic number, because the mean of its divisors is an integer number (432864276).

Almost surely, 2^865728551 is an apocalyptic number.

865728551 is a deficient number, since it is larger than the sum of its proper divisors (1).

865728551 is an equidigital number, since it uses as much as digits as its factorization.

865728551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672000, while the sum is 47.

The square root of 865728551 is about 29423.2654713919. The cubic root of 865728551 is about 953.0753709620.

The spelling of 865728551 in words is "eight hundred sixty-five million, seven hundred twenty-eight thousand, five hundred fifty-one".