1998280 has 16 divisors (see below), whose sum is σ = 4496220. Its totient is φ = 799296.

The previous prime is 1998277. The next prime is 1998289. The reversal of 1998280 is 828991.

It can be written as a sum of positive squares in 2 ways, for example, as 1920996 + 77284 = 1386^2 + 278^2 .

It is not an unprimeable number, because it can be changed into a prime (1998289) 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 3 ways as a sum of consecutive naturals, for example, 24939 + ... + 25018.

2^1998280 is an apocalyptic number.

1998280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1998280 is an abundant number, since it is smaller than the sum of its proper divisors (2497940).

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

1998280 is a wasteful number, since it uses less digits than its factorization.

1998280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49968 (or 49964 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 1998280 is about 1413.6053197410. The cubic root of 1998280 is about 125.9559768940.

It can be divided in two parts, 1998 and 280, that added together give a triangular number (2278 = T₆₇).

The spelling of 1998280 in words is "one million, nine hundred ninety-eight thousand, two hundred eighty".