1981814413 has 2 divisors, whose sum is σ = 1981814414. Its totient is φ = 1981814412.

The previous prime is 1981814371. The next prime is 1981814447. The reversal of 1981814413 is 3144181891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1684527849 + 297286564 = 41043^2 + 17242^2 .

It is a cyclic number.

It is not a de Polignac number, because 1981814413 - 2²⁹ = 1444943501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1981814713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990907206 + 990907207.

It is an arithmetic number, because the mean of its divisors is an integer number (990907207).

Almost surely, 2^1981814413 is an apocalyptic number.

It is an amenable number.

1981814413 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981814413 is an equidigital number, since it uses as much as digits as its factorization.

1981814413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27648, while the sum is 40.

The square root of 1981814413 is about 44517.5742039029. The cubic root of 1981814413 is about 1256.0906827723.

The spelling of 1981814413 in words is "one billion, nine hundred eighty-one million, eight hundred fourteen thousand, four hundred thirteen".