1981081579 has 2 divisors, whose sum is σ = 1981081580. Its totient is φ = 1981081578.

The previous prime is 1981081573. The next prime is 1981081667. The reversal of 1981081579 is 9751801891.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1981081579 - 2¹³ = 1981073387 is a prime.

It is not a weakly prime, because it can be changed into another prime (1981081573) 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, 990540789 + 990540790.

It is an arithmetic number, because the mean of its divisors is an integer number (990540790).

Almost surely, 2^1981081579 is an apocalyptic number.

1981081579 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981081579 is an equidigital number, since it uses as much as digits as its factorization.

1981081579 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 49.

The square root of 1981081579 is about 44509.3426035479. The cubic root of 1981081579 is about 1255.9358382288.

The spelling of 1981081579 in words is "one billion, nine hundred eighty-one million, eighty-one thousand, five hundred seventy-nine".