865945549549 has 2 divisors, whose sum is σ = 865945549550. Its totient is φ = 865945549548.

The previous prime is 865945549537. The next prime is 865945549571. The reversal of 865945549549 is 945945549568.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 686926016100 + 179019533449 = 828810^2 + 423107^2 .

It is a cyclic number.

It is not a de Polignac number, because 865945549549 - 2¹¹ = 865945547501 is a prime.

It is a super-2 number, since 2×865945549549² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (865945549349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432972774774 + 432972774775.

It is an arithmetic number, because the mean of its divisors is an integer number (432972774775).

Almost surely, 2^865945549549 is an apocalyptic number.

It is an amenable number.

865945549549 is a deficient number, since it is larger than the sum of its proper divisors (1).

865945549549 is an equidigital number, since it uses as much as digits as its factorization.

865945549549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1399680000, while the sum is 73.

The spelling of 865945549549 in words is "eight hundred sixty-five billion, nine hundred forty-five million, five hundred forty-nine thousand, five hundred forty-nine".