866441785258623 has 16 divisors (see below), whose sum is σ = 1326994235297280. Its totient is φ = 492596344916256.

The previous prime is 866441785258613. The next prime is 866441785258639. The reversal of 866441785258623 is 326852587144668.

It is not a de Polignac number, because 866441785258623 - 2¹⁶ = 866441785193087 is a prime.

It is a super-2 number, since 2×866441785258623² (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 (866441785258613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104718606603 + ... + 104718614876.

It is an arithmetic number, because the mean of its divisors is an integer number (82937139706080).

Almost surely, 2^{866441785258623} is an apocalyptic number.

866441785258623 is a deficient number, since it is larger than the sum of its proper divisors (460552450038657).

866441785258623 is a wasteful number, since it uses less digits than its factorization.

866441785258623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209437221686.

The product of its digits is 3715891200, while the sum is 75.

The spelling of 866441785258623 in words is "eight hundred sixty-six trillion, four hundred forty-one billion, seven hundred eighty-five million, two hundred fifty-eight thousand, six hundred twenty-three".