209474129 has 4 divisors (see below), whose sum is σ = 211396020. Its totient is φ = 207552240.

The previous prime is 209474077. The next prime is 209474141. The reversal of 209474129 is 921474902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 147064129 + 62410000 = 12127^2 + 7900^2 .

It is a cyclic number.

It is not a de Polignac number, because 209474129 - 2²⁴ = 192696913 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 209474092 and 209474101.

It is not an unprimeable number, because it can be changed into a prime (209474149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 960782 + ... + 960999.

It is an arithmetic number, because the mean of its divisors is an integer number (52849005).

Almost surely, 2^209474129 is an apocalyptic number.

It is an amenable number.

209474129 is a deficient number, since it is larger than the sum of its proper divisors (1921891).

209474129 is a wasteful number, since it uses less digits than its factorization.

209474129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1921890.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 209474129 is about 14473.2210996723. The cubic root of 209474129 is about 593.8956319559.

The spelling of 209474129 in words is "two hundred nine million, four hundred seventy-four thousand, one hundred twenty-nine".