18773644786721 has 32 divisors (see below), whose sum is σ = 20939009908608. Its totient is φ = 16687055024640.

The previous prime is 18773644786703. The next prime is 18773644786733. The reversal of 18773644786721 is 12768744637781.

It is not a de Polignac number, because 18773644786721 - 2¹⁰ = 18773644785697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18773644786021) 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 31 ways as a sum of consecutive naturals, for example, 196714211 + ... + 196809623.

It is an arithmetic number, because the mean of its divisors is an integer number (654344059644).

Almost surely, 2^{18773644786721} is an apocalyptic number.

18773644786721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18773644786721 is a deficient number, since it is larger than the sum of its proper divisors (2165365121887).

18773644786721 is a wasteful number, since it uses less digits than its factorization.

18773644786721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96641.

The product of its digits is 531062784, while the sum is 71.

The spelling of 18773644786721 in words is "eighteen trillion, seven hundred seventy-three billion, six hundred forty-four million, seven hundred eighty-six thousand, seven hundred twenty-one".