1921817995775 has 6 divisors (see below), whose sum is σ = 2383054314792. Its totient is φ = 1537454396600.

The previous prime is 1921817995717. The next prime is 1921817995819. The reversal of 1921817995775 is 5775997181291.

It is not a de Polignac number, because 1921817995775 - 2¹⁶ = 1921817930239 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1921817995699 and 1921817995708.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38436359891 + ... + 38436359940.

It is an arithmetic number, because the mean of its divisors is an integer number (397175719132).

Almost surely, 2^{1921817995775} is an apocalyptic number.

1921817995775 is a deficient number, since it is larger than the sum of its proper divisors (461236319017).

1921817995775 is an equidigital number, since it uses as much as digits as its factorization.

1921817995775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76872719841 (or 76872719836 counting only the distinct ones).

The product of its digits is 100018800, while the sum is 71.

The spelling of 1921817995775 in words is "one trillion, nine hundred twenty-one billion, eight hundred seventeen million, nine hundred ninety-five thousand, seven hundred seventy-five".