1998399047 has 4 divisors (see below), whose sum is σ = 1998502440. Its totient is φ = 1998295656.

The previous prime is 1998399041. The next prime is 1998399083. The reversal of 1998399047 is 7409938991.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1998399047 - 2¹⁰ = 1998398023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998399041) 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 in 3 ways as a sum of consecutive naturals, for example, 13097 + ... + 64562.

It is an arithmetic number, because the mean of its divisors is an integer number (499625610).

Almost surely, 2^1998399047 is an apocalyptic number.

1998399047 is a deficient number, since it is larger than the sum of its proper divisors (103393).

1998399047 is an equidigital number, since it uses as much as digits as its factorization.

1998399047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103392.

The product of its (nonzero) digits is 4408992, while the sum is 59.

The square root of 1998399047 is about 44703.4567679055. The cubic root of 1998399047 is about 1259.5847810897.

The spelling of 1998399047 in words is "one billion, nine hundred ninety-eight million, three hundred ninety-nine thousand, forty-seven".