1998151680 has 448 divisors, whose sum is σ = 7700272128. Its totient is φ = 432537600.

The previous prime is 1998151669. The next prime is 1998151691. The reversal of 1998151680 is 861518991.

It is an interprime number because it is at equal distance from previous prime (1998151669) and next prime (1998151691).

It is a tau number, because it is divible by the number of its divisors (448).

It is a super-2 number, since 2×1998151680² = 7985220272573644800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19783630 + ... + 19783730.

Almost surely, 2^1998151680 is an apocalyptic number.

1998151680 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 1998151680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3850136064).

1998151680 is an abundant number, since it is smaller than the sum of its proper divisors (5702120448).

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

1998151680 is a wasteful number, since it uses less digits than its factorization.

1998151680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 48.

The square root of 1998151680 is about 44700.6899275615. The cubic root of 1998151680 is about 1259.5328073917.

The spelling of 1998151680 in words is "one billion, nine hundred ninety-eight million, one hundred fifty-one thousand, six hundred eighty".