1998656 has 56 divisors (see below), whose sum is σ = 4608576. Its totient is φ = 849920.

The previous prime is 1998643. The next prime is 1998679. The reversal of 1998656 is 6568991.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11885 + ... + 12051.

It is an arithmetic number, because the mean of its divisors is an integer number (82296).

2^1998656 is an apocalyptic number.

1998656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1998656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2304288).

1998656 is an abundant number, since it is smaller than the sum of its proper divisors (2609920).

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

1998656 is a wasteful number, since it uses less digits than its factorization.

1998656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 197 counting only the distinct ones).

The product of its digits is 116640, while the sum is 44.

The square root of 1998656 is about 1413.7383067598. The cubic root of 1998656 is about 125.9638764338.

The spelling of 1998656 in words is "one million, nine hundred ninety-eight thousand, six hundred fifty-six".