1981168851600 has 135 divisors (see below), whose sum is σ = 6875499325513. Its totient is φ = 528289173120.

The previous prime is 1981168851593. The next prime is 1981168851773. The reversal of 1981168851600 is 61588611891.

The square root of 1981168851600 is 1407540.

It is a perfect power (a square), and thus also a powerful number.

1981168851600 is a `hidden beast` number, since 1 + 9 + 8 + 116 + 8 + 8 + 516 + 0 + 0 = 666.

It can be written as a sum of positive squares in only one way, i.e., 713220786576 + 1267948065024 = 844524^2 + 1126032^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 84440671 + ... + 84464129.

Almost surely, 2^{1981168851600} is an apocalyptic number.

1981168851600 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1981168851600 is the 1407540-th square number.

It is an amenable number.

1981168851600 is an abundant number, since it is smaller than the sum of its proper divisors (4894330473913).

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

1981168851600 is an frugal number, since it uses more digits than its factorization.

1981168851600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46942 (or 23469 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 54.

The spelling of 1981168851600 in words is "one trillion, nine hundred eighty-one billion, one hundred sixty-eight million, eight hundred fifty-one thousand, six hundred".