213909 has 8 divisors (see below), whose sum is σ = 288192. Its totient is φ = 141120.

The previous prime is 213901. The next prime is 213919. The reversal of 213909 is 909312.

It is a happy number.

213909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 213909 - 2³ = 213901 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 213909.

It is not an unprimeable number, because it can be changed into a prime (213901) 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, 24 + ... + 654.

It is an arithmetic number, because the mean of its divisors is an integer number (36024).

2²¹³⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

213909 is a deficient number, since it is larger than the sum of its proper divisors (74283).

213909 is a wasteful number, since it uses less digits than its factorization.

213909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747.

The product of its (nonzero) digits is 486, while the sum is 24.

The square root of 213909 is about 462.5029729634. The cubic root of 213909 is about 59.8057607527.

It can be divided in two parts, 21390 and 9, that multiplied together give a triangular number (192510 = T₆₂₀).

The spelling of 213909 in words is "two hundred thirteen thousand, nine hundred nine".