188681393 has 4 divisors (see below), whose sum is σ = 190626660. Its totient is φ = 186736128.

The previous prime is 188681369. The next prime is 188681401. The reversal of 188681393 is 393186881.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 393186881 = 97 ⋅4053473.

It can be written as a sum of positive squares in 2 ways, for example, as 89340304 + 99341089 = 9452^2 + 9967^2 .

It is a cyclic number.

It is not a de Polignac number, because 188681393 - 2⁸ = 188681137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (188681993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 972488 + ... + 972681.

It is an arithmetic number, because the mean of its divisors is an integer number (47656665).

Almost surely, 2^188681393 is an apocalyptic number.

It is an amenable number.

188681393 is a deficient number, since it is larger than the sum of its proper divisors (1945267).

188681393 is an equidigital number, since it uses as much as digits as its factorization.

188681393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1945266.

The product of its digits is 248832, while the sum is 47.

The square root of 188681393 is about 13736.1345727246. The cubic root of 188681393 is about 573.5567008318.

The spelling of 188681393 in words is "one hundred eighty-eight million, six hundred eighty-one thousand, three hundred ninety-three".