188243681 has 4 divisors (see below), whose sum is σ = 188422164. Its totient is φ = 188065200.

The previous prime is 188243663. The next prime is 188243717. The reversal of 188243681 is 186342881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186342881 = 5557 ⋅33533.

It can be written as a sum of positive squares in 2 ways, for example, as 64144081 + 124099600 = 8009^2 + 11140^2 .

It is a cyclic number.

It is not a de Polignac number, because 188243681 - 2²² = 184049377 is a prime.

It is a super-2 number, since 2×188243681² = 70871366872859522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (188243641) 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, 87650 + ... + 89771.

It is an arithmetic number, because the mean of its divisors is an integer number (47105541).

Almost surely, 2^188243681 is an apocalyptic number.

It is an amenable number.

188243681 is a deficient number, since it is larger than the sum of its proper divisors (178483).

188243681 is a wasteful number, since it uses less digits than its factorization.

188243681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178482.

The product of its digits is 73728, while the sum is 41.

The square root of 188243681 is about 13720.1924549184. The cubic root of 188243681 is about 573.1128361210.

The spelling of 188243681 in words is "one hundred eighty-eight million, two hundred forty-three thousand, six hundred eighty-one".