865545557 has 2 divisors, whose sum is σ = 865545558. Its totient is φ = 865545556.

The previous prime is 865545539. The next prime is 865545631. The reversal of 865545557 is 755545568.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 737719921 + 127825636 = 27161^2 + 11306^2 .

It is a cyclic number.

It is not a de Polignac number, because 865545557 - 2²⁰ = 864496981 is a prime.

It is a super-2 number, since 2×865545557² = 1498338222484880498, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (865541557) 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, 432772778 + 432772779.

It is an arithmetic number, because the mean of its divisors is an integer number (432772779).

Almost surely, 2^865545557 is an apocalyptic number.

It is an amenable number.

865545557 is a deficient number, since it is larger than the sum of its proper divisors (1).

865545557 is an equidigital number, since it uses as much as digits as its factorization.

865545557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4200000, while the sum is 50.

The square root of 865545557 is about 29420.1556250133. The cubic root of 865545557 is about 953.0082138976.

The spelling of 865545557 in words is "eight hundred sixty-five million, five hundred forty-five thousand, five hundred fifty-seven".