1981782443 has 2 divisors, whose sum is σ = 1981782444. Its totient is φ = 1981782442.

The previous prime is 1981782433. The next prime is 1981782469. The reversal of 1981782443 is 3442871891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1981782443 - 2¹⁶ = 1981716907 is a prime.

It is not a weakly prime, because it can be changed into another prime (1981782433) 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 as a sum of consecutive naturals, namely, 990891221 + 990891222.

It is an arithmetic number, because the mean of its divisors is an integer number (990891222).

Almost surely, 2^1981782443 is an apocalyptic number.

1981782443 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981782443 is an equidigital number, since it uses as much as digits as its factorization.

1981782443 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 47.

The square root of 1981782443 is about 44517.2151307783. The cubic root of 1981782443 is about 1256.0839284508.

The spelling of 1981782443 in words is "one billion, nine hundred eighty-one million, seven hundred eighty-two thousand, four hundred forty-three".