816648318861 has 4 divisors (see below), whose sum is σ = 1088864425152. Its totient is φ = 544432212572.

The previous prime is 816648318641. The next prime is 816648318877. The reversal of 816648318861 is 168813846618.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 816648318861 - 2¹⁸ = 816648056717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 816648318795 and 816648318804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816648318961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136108053141 + ... + 136108053146.

It is an arithmetic number, because the mean of its divisors is an integer number (272216106288).

Almost surely, 2^816648318861 is an apocalyptic number.

It is an amenable number.

816648318861 is a deficient number, since it is larger than the sum of its proper divisors (272216106291).

816648318861 is a wasteful number, since it uses less digits than its factorization.

816648318861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272216106290.

The product of its digits is 10616832, while the sum is 60.

The spelling of 816648318861 in words is "eight hundred sixteen billion, six hundred forty-eight million, three hundred eighteen thousand, eight hundred sixty-one".