81878687818 has 8 divisors (see below), whose sum is σ = 129282138720. Its totient is φ = 38784641580.

The previous prime is 81878687801. The next prime is 81878687843.

81878687818 is nontrivially palindromic in base 10.

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

It is a super-2 number, since 2×81878687818² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1077351118 + ... + 1077351193.

It is an arithmetic number, because the mean of its divisors is an integer number (16160267340).

Almost surely, 2^81878687818 is an apocalyptic number.

81878687818 is a deficient number, since it is larger than the sum of its proper divisors (47403450902).

81878687818 is a wasteful number, since it uses less digits than its factorization.

81878687818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2154702332.

The product of its digits is 77070336, while the sum is 70.

The spelling of 81878687818 in words is "eighty-one billion, eight hundred seventy-eight million, six hundred eighty-seven thousand, eight hundred eighteen".