213409 has 8 divisors (see below), whose sum is σ = 249920. Its totient is φ = 178416.
The previous prime is 213407. The next prime is 213449. The reversal of 213409 is 904312.
It is a sphenic number, since it is the product of 3 distinct primes.
It is not a de Polignac number, because 213409 - 21 = 213407 is a prime.
It is a Duffinian number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (213407) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54 + ... + 655.
It is an arithmetic number, because the mean of its divisors is an integer number (31240).
2213409 is an apocalyptic number.
It is an amenable number.
213409 is a deficient number, since it is larger than the sum of its proper divisors (36511).
213409 is an equidigital number, since it uses as much as digits as its factorization.
213409 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 759.
The product of its (nonzero) digits is 216, while the sum is 19.
The square root of 213409 is about 461.9621196592. The cubic root of 213409 is about 59.7591268890.
The spelling of 213409 in words is "two hundred thirteen thousand, four hundred nine".
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