1998847 has 4 divisors (see below), whose sum is σ = 2001856. Its totient is φ = 1995840.

The previous prime is 1998839. The next prime is 1998881. The reversal of 1998847 is 7488991.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1998847 - 2³ = 1998839 is a prime.

It is a Duffinian number.

1998847 is a lucky number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 1998797 and 1998806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18 + ... + 1999.

It is an arithmetic number, because the mean of its divisors is an integer number (500464).

2^1998847 is an apocalyptic number.

1998847 is a deficient number, since it is larger than the sum of its proper divisors (3009).

1998847 is an equidigital number, since it uses as much as digits as its factorization.

1998847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3008.

The product of its digits is 145152, while the sum is 46.

The square root of 1998847 is about 1413.8058565447. The cubic root of 1998847 is about 125.9678888525.

The spelling of 1998847 in words is "one million, nine hundred ninety-eight thousand, eight hundred forty-seven".