8166812505851 has 4 divisors (see below), whose sum is σ = 8166819971952. Its totient is φ = 8166805039752.

The previous prime is 8166812505833. The next prime is 8166812505893. The reversal of 8166812505851 is 1585052186618.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 8166812505851 - 2³⁸ = 7891934598907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8166812505811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1736240 + ... + 4398653.

It is an arithmetic number, because the mean of its divisors is an integer number (2041704992988).

Almost surely, 2^{8166812505851} is an apocalyptic number.

8166812505851 is a deficient number, since it is larger than the sum of its proper divisors (7466101).

8166812505851 is a wasteful number, since it uses less digits than its factorization.

8166812505851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7466100.

The product of its (nonzero) digits is 4608000, while the sum is 56.

The spelling of 8166812505851 in words is "eight trillion, one hundred sixty-six billion, eight hundred twelve million, five hundred five thousand, eight hundred fifty-one".