189181440 has 640 divisors, whose sum is σ = 848517120. Its totient is φ = 38928384.

The previous prime is 189181429. The next prime is 189181477. The reversal of 189181440 is 44181981.

It is a tau number, because it is divible by the number of its divisors (640).

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 = 189181395 and 189181404.

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 63 ways as a sum of consecutive naturals, for example, 8225269 + ... + 8225291.

It is an arithmetic number, because the mean of its divisors is an integer number (1325808).

Almost surely, 2^189181440 is an apocalyptic number.

189181440 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 189181440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (424258560).

189181440 is an abundant number, since it is smaller than the sum of its proper divisors (659335680).

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

189181440 is a wasteful number, since it uses less digits than its factorization.

189181440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 189181440 is about 13754.3244108898. The cubic root of 189181440 is about 574.0629374913.

The spelling of 189181440 in words is "one hundred eighty-nine million, one hundred eighty-one thousand, four hundred forty".