188720385 has 16 divisors (see below), whose sum is σ = 345088896. Its totient is φ = 86272128.

The previous prime is 188720381. The next prime is 188720401. The reversal of 188720385 is 583027881.

It is a happy number.

188720385 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 188720385 - 2² = 188720381 is a prime.

It is not an unprimeable number, because it can be changed into a prime (188720381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 898564 + ... + 898773.

It is an arithmetic number, because the mean of its divisors is an integer number (21568056).

Almost surely, 2^188720385 is an apocalyptic number.

188720385 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

188720385 is a deficient number, since it is larger than the sum of its proper divisors (156368511).

188720385 is a wasteful number, since it uses less digits than its factorization.

188720385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1797352.

The product of its (nonzero) digits is 107520, while the sum is 42.

The square root of 188720385 is about 13737.5538215506. The cubic root of 188720385 is about 573.5962076112.

The spelling of 188720385 in words is "one hundred eighty-eight million, seven hundred twenty thousand, three hundred eighty-five".