198987840 has 196 divisors, whose sum is σ = 711267564. Its totient is φ = 53001216.

The previous prime is 198987827. The next prime is 198987847. The reversal of 198987840 is 48789891.

It can be written as a sum of positive squares in 2 ways, for example, as 36578304 + 162409536 = 6048^2 + 12744^2 .

It is a super-3 number, since 3×198987840³ (a number of 26 digits) contains 333 as substring.

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 (198987847) by changing a digit.

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 27 ways as a sum of consecutive naturals, for example, 232854 + ... + 233706.

Almost surely, 2^198987840 is an apocalyptic number.

198987840 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 198987840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (355633782).

198987840 is an abundant number, since it is smaller than the sum of its proper divisors (512279724).

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

198987840 is an frugal number, since it uses more digits than its factorization.

198987840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 888 (or 863 counting only the distinct ones).

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

The square root of 198987840 is about 14106.3049733089. The cubic root of 198987840 is about 583.8153541485.

The spelling of 198987840 in words is "one hundred ninety-eight million, nine hundred eighty-seven thousand, eight hundred forty".