188665313 has 4 divisors (see below), whose sum is σ = 193266948. Its totient is φ = 184063680.

The previous prime is 188665259. The next prime is 188665327. The reversal of 188665313 is 313566881.

188665313 = 9712² + 9713².

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 94322944 + 94342369 = 9712^2 + 9713^2 .

It is a cyclic number.

It is not a de Polignac number, because 188665313 - 2⁶ = 188665249 is a prime.

It is a super-4 number, since 4×188665313⁴ (a number of 34 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 4601593 = 188665313 / (1 + 8 + 8 + 6 + 6 + 5 + 3 + 1 + 3).

It is not an unprimeable number, because it can be changed into a prime (188665013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2300756 + ... + 2300837.

It is an arithmetic number, because the mean of its divisors is an integer number (48316737).

Almost surely, 2^188665313 is an apocalyptic number.

188665313 is the 9713-rd centered square number.

It is an amenable number.

188665313 is a deficient number, since it is larger than the sum of its proper divisors (4601635).

188665313 is an equidigital number, since it uses as much as digits as its factorization.

188665313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4601634.

The product of its digits is 103680, while the sum is 41.

The square root of 188665313 is about 13735.5492427496. The cubic root of 188665313 is about 573.5404069556.

The spelling of 188665313 in words is "one hundred eighty-eight million, six hundred sixty-five thousand, three hundred thirteen".