866181771365878 has 16 divisors (see below), whose sum is σ = 1417400882853120. Its totient is φ = 393715506509800.

The previous prime is 866181771365797. The next prime is 866181771365899. The reversal of 866181771365878 is 878563177181668.

It is a super-2 number, since 2×866181771365878² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171477658 + ... + 176456653.

It is an arithmetic number, because the mean of its divisors is an integer number (88587555178320).

Almost surely, 2^{866181771365878} is an apocalyptic number.

866181771365878 is a deficient number, since it is larger than the sum of its proper divisors (551219111487242).

866181771365878 is a wasteful number, since it uses less digits than its factorization.

866181771365878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348047483.

The product of its digits is 4551966720, while the sum is 82.

The spelling of 866181771365878 in words is "eight hundred sixty-six trillion, one hundred eighty-one billion, seven hundred seventy-one million, three hundred sixty-five thousand, eight hundred seventy-eight".