1981317940992 has 432 divisors, whose sum is σ = 6797202205248. Its totient is φ = 548825333760.

The previous prime is 1981317940957. The next prime is 1981317940997. The reversal of 1981317940992 is 2990497131891.

It is a happy number.

1981317940992 is a `hidden beast` number, since 1 + 9 + 8 + 131 + 7 + 9 + 409 + 92 = 666.

It is a super-3 number, since 3×1981317940992³ (a number of 38 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981317940997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11626642 + ... + 11795822.

It is an arithmetic number, because the mean of its divisors is an integer number (15734264364).

Almost surely, 2^{1981317940992} is an apocalyptic number.

1981317940992 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1981317940992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3398601102624).

1981317940992 is an abundant number, since it is smaller than the sum of its proper divisors (4815884264256).

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

1981317940992 is a wasteful number, since it uses less digits than its factorization.

1981317940992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169256 (or 169239 counting only the distinct ones).

The product of its (nonzero) digits is 8817984, while the sum is 63.

The spelling of 1981317940992 in words is "one trillion, nine hundred eighty-one billion, three hundred seventeen million, nine hundred forty thousand, nine hundred ninety-two".