1998278208 has 112 divisors (see below), whose sum is σ = 5898245760. Its totient is φ = 663409152.

The previous prime is 1998278207. The next prime is 1998278221. The reversal of 1998278208 is 8028728991.

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

It is not an unprimeable number, because it can be changed into a prime (1998278207) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 452266 + ... + 456662.

Almost surely, 2^1998278208 is an apocalyptic number.

1998278208 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 1998278208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2949122880).

1998278208 is an abundant number, since it is smaller than the sum of its proper divisors (3899967552).

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

1998278208 is a wasteful number, since it uses less digits than its factorization.

1998278208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4681 (or 4665 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 54.

The square root of 1998278208 is about 44702.1051853266. The cubic root of 1998278208 is about 1259.5593924278.

The spelling of 1998278208 in words is "one billion, nine hundred ninety-eight million, two hundred seventy-eight thousand, two hundred eight".