188640 has 72 divisors (see below), whose sum is σ = 648648. Its totient is φ = 49920.

The previous prime is 188633. The next prime is 188653. The reversal of 188640 is 46881.

188640 is a `hidden beast` number, since 18 + 8 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

188640 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1375 + ... + 1505.

It is an arithmetic number, because the mean of its divisors is an integer number (9009).

2¹⁸⁸⁶⁴⁰ is an apocalyptic number.

188640 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 188640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324324).

188640 is an abundant number, since it is smaller than the sum of its proper divisors (460008).

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

188640 is a wasteful number, since it uses less digits than its factorization.

188640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 188640 is about 434.3270657005. The cubic root of 188640 is about 57.3514755398.

It can be divided in two parts, 188 and 640, that added together give a palindrome (828).

The spelling of 188640 in words is "one hundred eighty-eight thousand, six hundred forty".