189921047 has 2 divisors, whose sum is σ = 189921048. Its totient is φ = 189921046.

The previous prime is 189921019. The next prime is 189921073. The reversal of 189921047 is 740129981.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 189921047 - 2²⁰ = 188872471 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 189920995 and 189921013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189921077) 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 as a sum of consecutive naturals, namely, 94960523 + 94960524.

It is an arithmetic number, because the mean of its divisors is an integer number (94960524).

Almost surely, 2^189921047 is an apocalyptic number.

189921047 is a deficient number, since it is larger than the sum of its proper divisors (1).

189921047 is an equidigital number, since it uses as much as digits as its factorization.

189921047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 41.

The square root of 189921047 is about 13781.1845281891. The cubic root of 189921047 is about 574.8100665689.

The spelling of 189921047 in words is "one hundred eighty-nine million, nine hundred twenty-one thousand, forty-seven".