866655444321 has 6 divisors (see below), whose sum is σ = 1251835641810. Its totient is φ = 577770296208.

The previous prime is 866655444313. The next prime is 866655444331. The reversal of 866655444321 is 123444556668.

It can be written as a sum of positive squares in only one way, i.e., 724948370721 + 141707073600 = 851439^2 + 376440^2 .

It is not a de Polignac number, because 866655444321 - 2³ = 866655444313 is a prime.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (866655444331) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 48147524676 + ... + 48147524693.

It is an arithmetic number, because the mean of its divisors is an integer number (208639273635).

Almost surely, 2^866655444321 is an apocalyptic number.

It is an amenable number.

866655444321 is a deficient number, since it is larger than the sum of its proper divisors (385180197489).

866655444321 is a wasteful number, since it uses less digits than its factorization.

866655444321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96295049375 (or 96295049372 counting only the distinct ones).

The product of its digits is 16588800, while the sum is 54.

The spelling of 866655444321 in words is "eight hundred sixty-six billion, six hundred fifty-five million, four hundred forty-four thousand, three hundred twenty-one".