209428971 has 8 divisors (see below), whose sum is σ = 279645504. Its totient is φ = 139415880.

The previous prime is 209428951. The next prime is 209428979. The reversal of 209428971 is 179824902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 209428971 - 2⁵ = 209428939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (209428979) 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 in 7 ways as a sum of consecutive naturals, for example, 48441 + ... + 52586.

It is an arithmetic number, because the mean of its divisors is an integer number (34955688).

Almost surely, 2^209428971 is an apocalyptic number.

209428971 is a deficient number, since it is larger than the sum of its proper divisors (70216533).

209428971 is a wasteful number, since it uses less digits than its factorization.

209428971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101721.

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 209428971 is about 14471.6609620320. The cubic root of 209428971 is about 593.8529519576.

The spelling of 209428971 in words is "two hundred nine million, four hundred twenty-eight thousand, nine hundred seventy-one".