1981544973696 has 96 divisors (see below), whose sum is σ = 5898726381600. Its totient is φ = 637738601472.

The previous prime is 1981544973643. The next prime is 1981544973701. The reversal of 1981544973696 is 6963794451891.

It is a happy number.

1981544973696 is a `hidden beast` number, since 1 + 9 + 8 + 1 + 544 + 9 + 73 + 6 + 9 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29623336 + ... + 29690151.

It is an arithmetic number, because the mean of its divisors is an integer number (61445066475).

Almost surely, 2^{1981544973696} is an apocalyptic number.

1981544973696 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1981544973696 is an abundant number, since it is smaller than the sum of its proper divisors (3917181407904).

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

1981544973696 is a wasteful number, since it uses less digits than its factorization.

1981544973696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59313536 (or 59313521 counting only the distinct ones).

The product of its digits is 352719360, while the sum is 72.

The spelling of 1981544973696 in words is "one trillion, nine hundred eighty-one billion, five hundred forty-four million, nine hundred seventy-three thousand, six hundred ninety-six".