188540321 has 2 divisors, whose sum is σ = 188540322. Its totient is φ = 188540320.

The previous prime is 188540267. The next prime is 188540323. The reversal of 188540321 is 123045881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 183982096 + 4558225 = 13564^2 + 2135^2 .

It is a cyclic number.

It is not a de Polignac number, because 188540321 - 2⁶ = 188540257 is a prime.

It is a Sophie Germain prime.

Together with 188540323, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (188540323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94270160 + 94270161.

It is an arithmetic number, because the mean of its divisors is an integer number (94270161).

Almost surely, 2^188540321 is an apocalyptic number.

It is an amenable number.

188540321 is a deficient number, since it is larger than the sum of its proper divisors (1).

188540321 is an equidigital number, since it uses as much as digits as its factorization.

188540321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 188540321 is about 13730.9985434418. The cubic root of 188540321 is about 573.4137208883.

The spelling of 188540321 in words is "one hundred eighty-eight million, five hundred forty thousand, three hundred twenty-one".