186828221 has 2 divisors, whose sum is σ = 186828222. Its totient is φ = 186828220.

The previous prime is 186828209. The next prime is 186828247. The reversal of 186828221 is 122828681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 146047225 + 40780996 = 12085^2 + 6386^2 .

It is an emirp because it is prime and its reverse (122828681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 186828221 - 2²⁶ = 119719357 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (186828251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93414110 + 93414111.

It is an arithmetic number, because the mean of its divisors is an integer number (93414111).

Almost surely, 2^186828221 is an apocalyptic number.

It is an amenable number.

186828221 is a deficient number, since it is larger than the sum of its proper divisors (1).

186828221 is an equidigital number, since it uses as much as digits as its factorization.

186828221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24576, while the sum is 38.

The square root of 186828221 is about 13668.5120258205. The cubic root of 186828221 is about 571.6727521992.

The spelling of 186828221 in words is "one hundred eighty-six million, eight hundred twenty-eight thousand, two hundred twenty-one".