1681863136818 has 8 divisors (see below), whose sum is σ = 3363726273648. Its totient is φ = 560621045604.

The previous prime is 1681863136817. The next prime is 1681863136823. The reversal of 1681863136818 is 8186313681861.

It is a happy number.

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

1681863136818 is an admirable number.

It is a super-2 number, since 2×1681863136818² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1681863136817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140155261396 + ... + 140155261407.

It is an arithmetic number, because the mean of its divisors is an integer number (420465784206).

Almost surely, 2^{1681863136818} is an apocalyptic number.

1681863136818 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1681863136818 is a wasteful number, since it uses less digits than its factorization.

1681863136818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280310522808.

The product of its digits is 7962624, while the sum is 60.

The spelling of 1681863136818 in words is "one trillion, six hundred eighty-one billion, eight hundred sixty-three million, one hundred thirty-six thousand, eight hundred eighteen".