1998831168 has 280 divisors, whose sum is σ = 6453771192. Its totient is φ = 609140736.

The previous prime is 1998831161. The next prime is 1998831173. The reversal of 1998831168 is 8611388991.

1998831168 is a `hidden beast` number, since 199 + 88 + 311 + 68 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 308634624 + 1690196544 = 17568^2 + 41112^2 .

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

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1998831161) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3260430 + ... + 3261042.

Almost surely, 2^1998831168 is an apocalyptic number.

1998831168 is a gapful number since it is divisible by the number (18) 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 1998831168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3226885596).

1998831168 is an abundant number, since it is smaller than the sum of its proper divisors (4454940024).

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

1998831168 is a wasteful number, since it uses less digits than its factorization.

1998831168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691 (or 672 counting only the distinct ones).

The product of its digits is 746496, while the sum is 54.

The square root of 1998831168 is about 44708.2897011281. The cubic root of 1998831168 is about 1259.6755627264.

The spelling of 1998831168 in words is "one billion, nine hundred ninety-eight million, eight hundred thirty-one thousand, one hundred sixty-eight".