866223738705855 has 16 divisors (see below), whose sum is σ = 1401530543526240. Its totient is φ = 456795140110848.

The previous prime is 866223738705851. The next prime is 866223738705863. The reversal of 866223738705855 is 558507837322668.

It is not a de Polignac number, because 866223738705855 - 2² = 866223738705851 is a prime.

It is a super-2 number, since 2×866223738705855² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866223738705851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 324428365222 + ... + 324428367891.

It is an arithmetic number, because the mean of its divisors is an integer number (87595658970390).

Almost surely, 2^{866223738705855} is an apocalyptic number.

866223738705855 is a deficient number, since it is larger than the sum of its proper divisors (535306804820385).

866223738705855 is a wasteful number, since it uses less digits than its factorization.

866223738705855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 648856733210.

The product of its (nonzero) digits is 4064256000, while the sum is 75.

The spelling of 866223738705855 in words is "eight hundred sixty-six trillion, two hundred twenty-three billion, seven hundred thirty-eight million, seven hundred five thousand, eight hundred fifty-five".