1984966885981 has 4 divisors (see below), whose sum is σ = 2002532964732. Its totient is φ = 1967400807232.

The previous prime is 1984966885963. The next prime is 1984966886003. The reversal of 1984966885981 is 1895886694891.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 597598572025 + 1387368313956 = 773045^2 + 1177866^2 .

It is a cyclic number.

It is not a de Polignac number, because 1984966885981 - 2³³ = 1976376951389 is a prime.

It is a super-2 number, since 2×1984966885981² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1984966885895 and 1984966885904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1984966885961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8783039206 + ... + 8783039431.

It is an arithmetic number, because the mean of its divisors is an integer number (500633241183).

Almost surely, 2^{1984966885981} is an apocalyptic number.

It is an amenable number.

1984966885981 is a deficient number, since it is larger than the sum of its proper divisors (17566078751).

1984966885981 is a wasteful number, since it uses less digits than its factorization.

1984966885981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17566078750.

The product of its digits is 2149908480, while the sum is 82.

The spelling of 1984966885981 in words is "one trillion, nine hundred eighty-four billion, nine hundred sixty-six million, eight hundred eighty-five thousand, nine hundred eighty-one".