1998881280 has 480 divisors, whose sum is σ = 7836998400. Its totient is φ = 482549760.

The previous prime is 1998881279. The next prime is 1998881293. The reversal of 1998881280 is 821888991.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8363401 + ... + 8363639.

It is an arithmetic number, because the mean of its divisors is an integer number (16327080).

Almost surely, 2^1998881280 is an apocalyptic number.

1998881280 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 1998881280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3918499200).

1998881280 is an abundant number, since it is smaller than the sum of its proper divisors (5838117120).

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

1998881280 is a wasteful number, since it uses less digits than its factorization.

1998881280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293 (or 260 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 54.

The square root of 1998881280 is about 44708.8501305949. The cubic root of 1998881280 is about 1259.6860896008.

The spelling of 1998881280 in words is "one billion, nine hundred ninety-eight million, eight hundred eighty-one thousand, two hundred eighty".