1998720 has 96 divisors (see below), whose sum is σ = 6921720. Its totient is φ = 531456.

The previous prime is 1998701. The next prime is 1998727. The reversal of 1998720 is 278991.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a zygodrome in base 2.

It is a congruent number.

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

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5587 + ... + 5933.

2^1998720 is an apocalyptic number.

1998720 is a gapful number since it is divisible by the number (10) 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 1998720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3460860).

1998720 is an abundant number, since it is smaller than the sum of its proper divisors (4923000).

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

1998720 is a wasteful number, since it uses less digits than its factorization.

1998720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 1998720 is about 1413.7609416022. The cubic root of 1998720 is about 125.9652209377.

The spelling of 1998720 in words is "one million, nine hundred ninety-eight thousand, seven hundred twenty".