209723147 has 2 divisors, whose sum is σ = 209723148. Its totient is φ = 209723146.

The previous prime is 209723123. The next prime is 209723179. The reversal of 209723147 is 741327902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 209723147 - 2¹² = 209719051 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (209722147) 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, 104861573 + 104861574.

It is an arithmetic number, because the mean of its divisors is an integer number (104861574).

Almost surely, 2^209723147 is an apocalyptic number.

209723147 is a deficient number, since it is larger than the sum of its proper divisors (1).

209723147 is an equidigital number, since it uses as much as digits as its factorization.

209723147 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 209723147 is about 14481.8212597725. The cubic root of 209723147 is about 594.1308752273.

The spelling of 209723147 in words is "two hundred nine million, seven hundred twenty-three thousand, one hundred forty-seven".