1981962139 has 2 divisors, whose sum is σ = 1981962140. Its totient is φ = 1981962138.

The previous prime is 1981962121. The next prime is 1981962173. The reversal of 1981962139 is 9312691891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1981962139 - 2⁵ = 1981962107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1981962092 and 1981962101.

It is not a weakly prime, because it can be changed into another prime (1981968139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990981069 + 990981070.

It is an arithmetic number, because the mean of its divisors is an integer number (990981070).

Almost surely, 2^1981962139 is an apocalyptic number.

1981962139 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981962139 is an equidigital number, since it uses as much as digits as its factorization.

1981962139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 49.

The square root of 1981962139 is about 44519.2333604252. The cubic root of 1981962139 is about 1256.1218919916.

The spelling of 1981962139 in words is "one billion, nine hundred eighty-one million, nine hundred sixty-two thousand, one hundred thirty-nine".