1998857143 has 2 divisors, whose sum is σ = 1998857144. Its totient is φ = 1998857142.

The previous prime is 1998857117. The next prime is 1998857149. The reversal of 1998857143 is 3417588991.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998857143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1998857149) 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, 999428571 + 999428572.

It is an arithmetic number, because the mean of its divisors is an integer number (999428572).

Almost surely, 2^1998857143 is an apocalyptic number.

1998857143 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998857143 is an equidigital number, since it uses as much as digits as its factorization.

1998857143 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2177280, while the sum is 55.

The square root of 1998857143 is about 44708.5801944101. The cubic root of 1998857143 is about 1259.6810192371.

It can be divided in two parts, 1998857 and 143, that added together give a triangular number (1999000 = T₁₉₉₉).

The spelling of 1998857143 in words is "one billion, nine hundred ninety-eight million, eight hundred fifty-seven thousand, one hundred forty-three".