1998724 has 72 divisors (see below), whose sum is σ = 4813760. Its totient is φ = 705024.

The previous prime is 1998701. The next prime is 1998727. The reversal of 1998724 is 4278991.

1998724 = 277² + 278² + ... + 300².

It is not an unprimeable number, because it can be changed into a prime (1998727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 105187 + ... + 105205.

2^1998724 is an apocalyptic number.

1998724 is a gapful number since it is divisible by the number (14) 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 1998724, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2406880).

1998724 is an abundant number, since it is smaller than the sum of its proper divisors (2815036).

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

1998724 is a wasteful number, since it uses less digits than its factorization.

1998724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77 (or 58 counting only the distinct ones).

The product of its digits is 36288, while the sum is 40.

The square root of 1998724 is about 1413.7623562678. The cubic root of 1998724 is about 125.9653049682.

The spelling of 1998724 in words is "one million, nine hundred ninety-eight thousand, seven hundred twenty-four".