866786278585031 has 4 divisors (see below), whose sum is σ = 990612889811472. Its totient is φ = 742959667358592.

The previous prime is 866786278584973. The next prime is 866786278585079. The reversal of 866786278585031 is 130585872687668.

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

It is a cyclic number.

It is not a de Polignac number, because 866786278585031 - 2¹⁰ = 866786278584007 is a prime.

It is a super-2 number, since 2×866786278585031² (a number of 31 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866786278588031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61913305613210 + ... + 61913305613223.

It is an arithmetic number, because the mean of its divisors is an integer number (247653222452868).

Almost surely, 2^{866786278585031} is an apocalyptic number.

866786278585031 is a deficient number, since it is larger than the sum of its proper divisors (123826611226441).

866786278585031 is a wasteful number, since it uses less digits than its factorization.

866786278585031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123826611226440.

The product of its (nonzero) digits is 6502809600, while the sum is 80.

The spelling of 866786278585031 in words is "eight hundred sixty-six trillion, seven hundred eighty-six billion, two hundred seventy-eight million, five hundred eighty-five thousand, thirty-one".