816809680186 has 8 divisors (see below), whose sum is σ = 1245300004404. Its totient is φ = 401709678720.

The previous prime is 816809680139. The next prime is 816809680187. The reversal of 816809680186 is 681086908618.

It can be written as a sum of positive squares in 2 ways, for example, as 644351371225 + 172458308961 = 802715^2 + 415281^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is not an unprimeable number, because it can be changed into a prime (816809680187) 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, 3347580535 + ... + 3347580778.

Almost surely, 2^816809680186 is an apocalyptic number.

816809680186 is a deficient number, since it is larger than the sum of its proper divisors (428490324218).

816809680186 is a wasteful number, since it uses less digits than its factorization.

816809680186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6695161376.

The product of its (nonzero) digits is 7962624, while the sum is 61.

The spelling of 816809680186 in words is "eight hundred sixteen billion, eight hundred nine million, six hundred eighty thousand, one hundred eighty-six".