1998016663 has 4 divisors (see below), whose sum is σ = 1999922400. Its totient is φ = 1996110928.

The previous prime is 1998016661. The next prime is 1998016667. The reversal of 1998016663 is 3666108991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3666108991 = 4243 ⋅864037.

It is a cyclic number.

It is not a de Polignac number, because 1998016663 - 2¹ = 1998016661 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998016661) 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, 951295 + ... + 953392.

It is an arithmetic number, because the mean of its divisors is an integer number (499980600).

Almost surely, 2^1998016663 is an apocalyptic number.

1998016663 is a deficient number, since it is larger than the sum of its proper divisors (1905737).

1998016663 is a wasteful number, since it uses less digits than its factorization.

1998016663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1905736.

The product of its (nonzero) digits is 419904, while the sum is 49.

The square root of 1998016663 is about 44699.1796680879. The cubic root of 1998016663 is about 1259.5044374782.

The spelling of 1998016663 in words is "one billion, nine hundred ninety-eight million, sixteen thousand, six hundred sixty-three".