1982981991 has 16 divisors (see below), whose sum is σ = 2735802368. Its totient is φ = 1276279200.

The previous prime is 1982981989. The next prime is 1982981993. The reversal of 1982981991 is 1991892891.

It is an interprime number because it is at equal distance from previous prime (1982981989) and next prime (1982981993).

It is not a de Polignac number, because 1982981991 - 2¹ = 1982981989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1982981993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13830 + ... + 64476.

It is an arithmetic number, because the mean of its divisors is an integer number (170987648).

Almost surely, 2^1982981991 is an apocalyptic number.

1982981991 is a deficient number, since it is larger than the sum of its proper divisors (752820377).

1982981991 is a wasteful number, since it uses less digits than its factorization.

1982981991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51102.

The product of its digits is 839808, while the sum is 57.

The square root of 1982981991 is about 44530.6859480067. The cubic root of 1982981991 is about 1256.3373079391.

The spelling of 1982981991 in words is "one billion, nine hundred eighty-two million, nine hundred eighty-one thousand, nine hundred ninety-one".