209989471 has 8 divisors (see below), whose sum is σ = 219533184. Its totient is φ = 200480280.

The previous prime is 209989459. The next prime is 209989487. The reversal of 209989471 is 174989902.

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

It is a cyclic number.

It is not a de Polignac number, because 209989471 - 2¹³ = 209981279 is a prime.

It is a super-3 number, since 3×209989471³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209989421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4236 + ... + 20926.

It is an arithmetic number, because the mean of its divisors is an integer number (27441648).

Almost surely, 2^209989471 is an apocalyptic number.

209989471 is a deficient number, since it is larger than the sum of its proper divisors (9543713).

209989471 is a wasteful number, since it uses less digits than its factorization.

209989471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17261.

The product of its (nonzero) digits is 326592, while the sum is 49.

The square root of 209989471 is about 14491.0134566220. The cubic root of 209989471 is about 594.3822612128.

The spelling of 209989471 in words is "two hundred nine million, nine hundred eighty-nine thousand, four hundred seventy-one".