2839391981 has 2 divisors, whose sum is σ = 2839391982. Its totient is φ = 2839391980.

The previous prime is 2839391927. The next prime is 2839391987. The reversal of 2839391981 is 1891939382.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1482943081 + 1356448900 = 38509^2 + 36830^2 .

It is a cyclic number.

It is not a de Polignac number, because 2839391981 - 2⁶ = 2839391917 is a prime.

It is a super-2 number, since 2×2839391981² = 16124293643534208722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2839391987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1419695990 + 1419695991.

It is an arithmetic number, because the mean of its divisors is an integer number (1419695991).

Almost surely, 2^2839391981 is an apocalyptic number.

It is an amenable number.

2839391981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2839391981 is an equidigital number, since it uses as much as digits as its factorization.

2839391981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 839808, while the sum is 53.

The square root of 2839391981 is about 53285.9454359215. The cubic root of 2839391981 is about 1416.0386819859.

The spelling of 2839391981 in words is "two billion, eight hundred thirty-nine million, three hundred ninety-one thousand, nine hundred eighty-one".