18273837381921 has 80 divisors (see below), whose sum is σ = 29838062295360. Its totient is φ = 11053318993920.

The previous prime is 18273837381911. The next prime is 18273837381949. The reversal of 18273837381921 is 12918373837281.

It is a happy number.

18273837381921 is a `hidden beast` number, since 1 + 8 + 2 + 73 + 8 + 373 + 8 + 192 + 1 = 666.

It is not a de Polignac number, because 18273837381921 - 2¹⁵ = 18273837349153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18273837381901) 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 79 ways as a sum of consecutive naturals, for example, 3119996625 + ... + 3120002481.

It is an arithmetic number, because the mean of its divisors is an integer number (372975778692).

Almost surely, 2^{18273837381921} is an apocalyptic number.

18273837381921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18273837381921 is a deficient number, since it is larger than the sum of its proper divisors (11564224913439).

18273837381921 is a wasteful number, since it uses less digits than its factorization.

18273837381921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12156 (or 12147 counting only the distinct ones).

The product of its digits is 24385536, while the sum is 63.

The spelling of 18273837381921 in words is "eighteen trillion, two hundred seventy-three billion, eight hundred thirty-seven million, three hundred eighty-one thousand, nine hundred twenty-one".