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198404640 = 2531157

198404640 has 288 divisors, whose sum is σ = 803537280. Its totient is φ = 45349632.

The previous prime is 198404561. The next prime is 198404651. The reversal of 198404640 is 46404891.

It is a happy number.

198404640 is a `hidden beast` number, since 1 + 9 + 8 + 4 + 0 + 4 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 198404595 and 198404604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28343517 + ... + 28343523.

It is an arithmetic number, because the mean of its divisors is an integer number (2790060).

Almost surely, 2198404640 is an apocalyptic number.

198404640 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 198404640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (401768640).

198404640 is an abundant number, since it is smaller than the sum of its proper divisors (605132640).

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

198404640 is an frugal number, since it uses more digits than its factorization.

198404640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 198404640 is about 14085.6181972961. The cubic root of 198404640 is about 583.2444410579.

The spelling of 198404640 in words is "one hundred ninety-eight million, four hundred four thousand, six hundred forty".