891040868663 has 4 divisors (see below), whose sum is σ = 972044584008. Its totient is φ = 810037153320.

The previous prime is 891040868647. The next prime is 891040868741. The reversal of 891040868663 is 366868040198.

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 891040868663 - 2⁴ = 891040868647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891040868063) 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 3 ways as a sum of consecutive naturals, for example, 40501857656 + ... + 40501857677.

It is an arithmetic number, because the mean of its divisors is an integer number (243011146002).

Almost surely, 2^891040868663 is an apocalyptic number.

891040868663 is a deficient number, since it is larger than the sum of its proper divisors (81003715345).

891040868663 is a wasteful number, since it uses less digits than its factorization.

891040868663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81003715344.

The product of its (nonzero) digits is 11943936, while the sum is 59.

The spelling of 891040868663 in words is "eight hundred ninety-one billion, forty million, eight hundred sixty-eight thousand, six hundred sixty-three".