1998839243 has 4 divisors (see below), whose sum is σ = 2116418040. Its totient is φ = 1881260448.

The previous prime is 1998839233. The next prime is 1998839251. The reversal of 1998839243 is 3429388991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998839243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1998839233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58789373 + ... + 58789406.

It is an arithmetic number, because the mean of its divisors is an integer number (529104510).

Almost surely, 2^1998839243 is an apocalyptic number.

1998839243 is a deficient number, since it is larger than the sum of its proper divisors (117578797).

1998839243 is a wasteful number, since it uses less digits than its factorization.

1998839243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117578796.

The product of its digits is 3359232, while the sum is 56.

The square root of 1998839243 is about 44708.3800086740. The cubic root of 1998839243 is about 1259.6772590288.

The spelling of 1998839243 in words is "one billion, nine hundred ninety-eight million, eight hundred thirty-nine thousand, two hundred forty-three".