209424 has 20 divisors (see below), whose sum is σ = 541136. Its totient is φ = 69792.

The previous prime is 209401. The next prime is 209431. The reversal of 209424 is 424902.

It is a super-3 number, since 3×209424³ = 27555012083331072, which contains 333 as substring.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 209424.

It is an unprimeable number.

209424 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2134 + ... + 2229.

2²⁰⁹⁴²⁴ is an apocalyptic number.

209424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

209424 is an abundant number, since it is smaller than the sum of its proper divisors (331712).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

209424 is a wasteful number, since it uses less digits than its factorization.

209424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4374 (or 4368 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 209424 is about 457.6286704305. The cubic root of 209424 is about 59.3848253362.

The spelling of 209424 in words is "two hundred nine thousand, four hundred twenty-four".