209851073 has 4 divisors (see below), whose sum is σ = 209986560. Its totient is φ = 209715588.

The previous prime is 209851069. The next prime is 209851091. The reversal of 209851073 is 370158902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 209851073 - 2² = 209851069 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (209851003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65393 + ... + 68526.

It is an arithmetic number, because the mean of its divisors is an integer number (52496640).

Almost surely, 2^209851073 is an apocalyptic number.

It is an amenable number.

209851073 is a deficient number, since it is larger than the sum of its proper divisors (135487).

209851073 is a wasteful number, since it uses less digits than its factorization.

209851073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135486.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 209851073 is about 14486.2373651684. The cubic root of 209851073 is about 594.2516524503.

The spelling of 209851073 in words is "two hundred nine million, eight hundred fifty-one thousand, seventy-three".