1981327496688 has 60 divisors (see below), whose sum is σ = 5553083966040. Its totient is φ = 659475493248.

The previous prime is 1981327496683. The next prime is 1981327496689. The reversal of 1981327496688 is 8866947231891.

1981327496688 is a `hidden beast` number, since 198 + 1 + 3 + 274 + 96 + 6 + 88 = 666.

It is a super-3 number, since 3×1981327496688³ (a number of 38 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981327496683) 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 11 ways as a sum of consecutive naturals, for example, 9974283 + ... + 10170986.

It is an arithmetic number, because the mean of its divisors is an integer number (92551399434).

Almost surely, 2^{1981327496688} is an apocalyptic number.

1981327496688 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1981327496688 is an abundant number, since it is smaller than the sum of its proper divisors (3571756469352).

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

1981327496688 is a wasteful number, since it uses less digits than its factorization.

1981327496688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20145966 (or 20145957 counting only the distinct ones).

The product of its digits is 250822656, while the sum is 72.

The spelling of 1981327496688 in words is "one trillion, nine hundred eighty-one billion, three hundred twenty-seven million, four hundred ninety-six thousand, six hundred eighty-eight".