189384721 has 2 divisors, whose sum is σ = 189384722. Its totient is φ = 189384720.

The previous prime is 189384707. The next prime is 189384731. The reversal of 189384721 is 127483981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189365121 + 19600 = 13761^2 + 140^2 .

It is a cyclic number.

It is not a de Polignac number, because 189384721 - 2⁷ = 189384593 is a prime.

It is not a weakly prime, because it can be changed into another prime (189384731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94692360 + 94692361.

It is an arithmetic number, because the mean of its divisors is an integer number (94692361).

Almost surely, 2^189384721 is an apocalyptic number.

It is an amenable number.

189384721 is a deficient number, since it is larger than the sum of its proper divisors (1).

189384721 is an equidigital number, since it uses as much as digits as its factorization.

189384721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 43.

The square root of 189384721 is about 13761.7121391199. The cubic root of 189384721 is about 574.2684797037.

The spelling of 189384721 in words is "one hundred eighty-nine million, three hundred eighty-four thousand, seven hundred twenty-one".