18913322331981 has 256 divisors, whose sum is σ = 36464217292800. Its totient is φ = 9400961606400.

The previous prime is 18913322331901. The next prime is 18913322331983.

It is a happy number.

18913322331981 is a `hidden beast` number, since 1 + 8 + 91 + 332 + 2 + 33 + 198 + 1 = 666.

18913322331981 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18913322331981 - 2⁷ = 18913322331853 is a prime.

It is a super-2 number, since 2×18913322331981² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18913322331983) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 8585256426 + ... + 8585258628.

It is an arithmetic number, because the mean of its divisors is an integer number (142438348800).

Almost surely, 2^{18913322331981} is an apocalyptic number.

18913322331981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18913322331981 is a deficient number, since it is larger than the sum of its proper divisors (17550894960819).

18913322331981 is a wasteful number, since it uses less digits than its factorization.

18913322331981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3477 (or 3471 counting only the distinct ones).

The product of its digits is 1679616, while the sum is 54.

The spelling of 18913322331981 in words is "eighteen trillion, nine hundred thirteen billion, three hundred twenty-two million, three hundred thirty-one thousand, nine hundred eighty-one".