1983993891 has 48 divisors (see below), whose sum is σ = 3116776320. Its totient is φ = 1109455360.

The previous prime is 1983993887. The next prime is 1983993937.

1983993891 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1983993891 - 2² = 1983993887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1983993871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1575220 + ... + 1576478.

It is an arithmetic number, because the mean of its divisors is an integer number (64932840).

Almost surely, 2^1983993891 is an apocalyptic number.

1983993891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1983993891 is a deficient number, since it is larger than the sum of its proper divisors (1132782429).

1983993891 is a wasteful number, since it uses less digits than its factorization.

1983993891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1396 (or 1343 counting only the distinct ones).

The product of its digits is 3779136, while the sum is 60.

The square root of 1983993891 is about 44542.0463270380. The cubic root of 1983993891 is about 1256.5509712580.

The spelling of 1983993891 in words is "one billion, nine hundred eighty-three million, nine hundred ninety-three thousand, eight hundred ninety-one".