1998725544 has 128 divisors (see below), whose sum is σ = 5703264000. Its totient is φ = 656449920.

The previous prime is 1998725537. The next prime is 1998725551. The reversal of 1998725544 is 4455278991.

It is a happy number.

1998725544 is a `hidden beast` number, since 1 + 9 + 9 + 87 + 2 + 554 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (1998725537) and next prime (1998725551).

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

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, 1241412 + ... + 1243020.

It is an arithmetic number, because the mean of its divisors is an integer number (44556750).

Almost surely, 2^1998725544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1998725544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2851632000).

1998725544 is an abundant number, since it is smaller than the sum of its proper divisors (3704538456).

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

1998725544 is an equidigital number, since it uses as much as digits as its factorization.

1998725544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1707 (or 1685 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 54.

The square root of 1998725544 is about 44707.1084280789. The cubic root of 1998725544 is about 1259.6533740397.

The spelling of 1998725544 in words is "one billion, nine hundred ninety-eight million, seven hundred twenty-five thousand, five hundred forty-four".