198781440 has 320 divisors, whose sum is σ = 750701952. Its totient is φ = 44236800.

The previous prime is 198781381. The next prime is 198781463. The reversal of 198781440 is 44187891.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 198781392 and 198781401.

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, 1098150 + ... + 1098330.

Almost surely, 2^198781440 is an apocalyptic number.

198781440 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 198781440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (375350976).

198781440 is an abundant number, since it is smaller than the sum of its proper divisors (551920512).

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

198781440 is a wasteful number, since it uses less digits than its factorization.

198781440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 42.

The square root of 198781440 is about 14098.9871976678. The cubic root of 198781440 is about 583.6134302926.

The spelling of 198781440 in words is "one hundred ninety-eight million, seven hundred eighty-one thousand, four hundred forty".