1998556 has 24 divisors (see below), whose sum is σ = 4034016. Its totient is φ = 848640.

The previous prime is 1998541. The next prime is 1998559. The reversal of 1998556 is 6558991.

It is a happy number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3576 + ... + 4096.

It is an arithmetic number, because the mean of its divisors is an integer number (168084).

2^1998556 is an apocalyptic number.

It is an amenable number.

1998556 is an abundant number, since it is smaller than the sum of its proper divisors (2035460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1998556 is a wasteful number, since it uses less digits than its factorization.

1998556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 669 (or 667 counting only the distinct ones).

The product of its digits is 97200, while the sum is 43.

The square root of 1998556 is about 1413.7029390929. The cubic root of 1998556 is about 125.9617755891.

The spelling of 1998556 in words is "one million, nine hundred ninety-eight thousand, five hundred fifty-six".