1998127320 has 128 divisors (see below), whose sum is σ = 7071805440. Its totient is φ = 441976320.

The previous prime is 1998127303. The next prime is 1998127331. The reversal of 1998127320 is 237218991.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 12327 + ... + 64406.

It is an arithmetic number, because the mean of its divisors is an integer number (55248480).

Almost surely, 2^1998127320 is an apocalyptic number.

1998127320 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 1998127320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3535902720).

1998127320 is an abundant number, since it is smaller than the sum of its proper divisors (5073678120).

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

1998127320 is a wasteful number, since it uses less digits than its factorization.

1998127320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76785 (or 76781 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 1998127320 is about 44700.4174477152. The cubic root of 1998127320 is about 1259.5276889375.

The spelling of 1998127320 in words is "one billion, nine hundred ninety-eight million, one hundred twenty-seven thousand, three hundred twenty".