1998785880 has 768 divisors, whose sum is σ = 8783873280. Its totient is φ = 382205952.

The previous prime is 1998785869. The next prime is 1998785891. The reversal of 1998785880 is 885878991.

It is an interprime number because it is at equal distance from previous prime (1998785869) and next prime (1998785891).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 20605992 + ... + 20606088.

It is an arithmetic number, because the mean of its divisors is an integer number (11437335).

Almost surely, 2^1998785880 is an apocalyptic number.

1998785880 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 1998785880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4391936640).

1998785880 is an abundant number, since it is smaller than the sum of its proper divisors (6785087400).

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

1998785880 is a wasteful number, since it uses less digits than its factorization.

1998785880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188 (or 181 counting only the distinct ones).

The product of its (nonzero) digits is 11612160, while the sum is 63.

The square root of 1998785880 is about 44707.7832150063. The cubic root of 1998785880 is about 1259.6660490635. Note that the first 3 decimals are identical.

The spelling of 1998785880 in words is "one billion, nine hundred ninety-eight million, seven hundred eighty-five thousand, eight hundred eighty".