188720640 has 120 divisors (see below), whose sum is σ = 653672448. Its totient is φ = 50319360.

The previous prime is 188720633. The next prime is 188720671. The reversal of 188720640 is 46027881.

188720640 is a `hidden beast` number, since 1 + 8 + 8 + 7 + 2 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

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 = 188720595 and 188720604.

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 11 ways as a sum of consecutive naturals, for example, 18945 + ... + 27135.

Almost surely, 2^188720640 is an apocalyptic number.

188720640 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 188720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326836224).

188720640 is an abundant number, since it is smaller than the sum of its proper divisors (464951808).

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

188720640 is an equidigital number, since it uses as much as digits as its factorization.

188720640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8220 (or 8201 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 188720640 is about 13737.5631026758. The cubic root of 188720640 is about 573.5964659598.

The spelling of 188720640 in words is "one hundred eighty-eight million, seven hundred twenty thousand, six hundred forty".