213609 has 8 divisors (see below), whose sum is σ = 310752. Its totient is φ = 129440.

The previous prime is 213599. The next prime is 213611. The reversal of 213609 is 906312.

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 213609 - 2⁷ = 213481 is a prime.

It is a plaindrome in base 14.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 213609.

It is not an unprimeable number, because it can be changed into a prime (213649) 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, 3204 + ... + 3269.

It is an arithmetic number, because the mean of its divisors is an integer number (38844).

2²¹³⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

213609 is a deficient number, since it is larger than the sum of its proper divisors (97143).

213609 is a wasteful number, since it uses less digits than its factorization.

213609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6487.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 213609 is about 462.1785369313. The cubic root of 213609 is about 59.7777891661. Note that the first 4 decimals are identical.

The spelling of 213609 in words is "two hundred thirteen thousand, six hundred nine".