189942209 has 2 divisors, whose sum is σ = 189942210. Its totient is φ = 189942208.

The previous prime is 189942191. The next prime is 189942229. The reversal of 189942209 is 902249981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180821809 + 9120400 = 13447^2 + 3020^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-189942209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 189942209.

It is not a weakly prime, because it can be changed into another prime (189942229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94971104 + 94971105.

It is an arithmetic number, because the mean of its divisors is an integer number (94971105).

Almost surely, 2^189942209 is an apocalyptic number.

It is an amenable number.

189942209 is a deficient number, since it is larger than the sum of its proper divisors (1).

189942209 is an equidigital number, since it uses as much as digits as its factorization.

189942209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 189942209 is about 13781.9522927632. The cubic root of 189942209 is about 574.8314152276.

The spelling of 189942209 in words is "one hundred eighty-nine million, nine hundred forty-two thousand, two hundred nine".