866788753824655 has 4 divisors (see below), whose sum is σ = 1040146504589592. Its totient is φ = 693431003059720.

The previous prime is 866788753824583. The next prime is 866788753824667. The reversal of 866788753824655 is 556428357887668.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-866788753824655 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86678875382461 + ... + 86678875382470.

It is an arithmetic number, because the mean of its divisors is an integer number (260036626147398).

Almost surely, 2^{866788753824655} is an apocalyptic number.

866788753824655 is a deficient number, since it is larger than the sum of its proper divisors (173357750764937).

866788753824655 is a wasteful number, since it uses less digits than its factorization.

866788753824655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173357750764936.

The product of its digits is 130056192000, while the sum is 88.

The spelling of 866788753824655 in words is "eight hundred sixty-six trillion, seven hundred eighty-eight billion, seven hundred fifty-three million, eight hundred twenty-four thousand, six hundred fifty-five".