866513800778847 has 16 divisors (see below), whose sum is σ = 1244249753134080. Its totient is φ = 533228629835232.

The previous prime is 866513800778771. The next prime is 866513800778897. The reversal of 866513800778847 is 748877008315668.

It is a de Polignac number, because none of the positive numbers 2^k-866513800778847 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866513800778897) 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, 219522523 + ... + 223434924.

It is an arithmetic number, because the mean of its divisors is an integer number (77765609570880).

Almost surely, 2^{866513800778847} is an apocalyptic number.

866513800778847 is a deficient number, since it is larger than the sum of its proper divisors (377735952355233).

866513800778847 is a wasteful number, since it uses less digits than its factorization.

866513800778847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443007622.

The product of its (nonzero) digits is 3034644480, while the sum is 78.

The spelling of 866513800778847 in words is "eight hundred sixty-six trillion, five hundred thirteen billion, eight hundred million, seven hundred seventy-eight thousand, eight hundred forty-seven".