209971233 has 24 divisors (see below), whose sum is σ = 325941408. Its totient is φ = 129773952.

The previous prime is 209971217. The next prime is 209971241. The reversal of 209971233 is 332179902.

It is not a de Polignac number, because 209971233 - 2⁴ = 209971217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (209971243) 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 in 23 ways as a sum of consecutive naturals, for example, 10 + ... + 20492.

It is an arithmetic number, because the mean of its divisors is an integer number (13580892).

Almost surely, 2^209971233 is an apocalyptic number.

It is an amenable number.

209971233 is a deficient number, since it is larger than the sum of its proper divisors (115970175).

209971233 is a wasteful number, since it uses less digits than its factorization.

209971233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20573 (or 20570 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 209971233 is about 14490.3841563983. The cubic root of 209971233 is about 594.3650529571.

The spelling of 209971233 in words is "two hundred nine million, nine hundred seventy-one thousand, two hundred thirty-three".