387209 has 4 divisors (see below), whose sum is σ = 410004. Its totient is φ = 364416.

The previous prime is 387203. The next prime is 387227. The reversal of 387209 is 902783.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 902783 = 7 ⋅128969.

It can be written as a sum of positive squares in 2 ways, for example, as 327184 + 60025 = 572^2 + 245^2 .

It is a cyclic number.

It is not a de Polignac number, because 387209 - 2¹² = 383113 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (387203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11372 + ... + 11405.

It is an arithmetic number, because the mean of its divisors is an integer number (102501).

2³⁸⁷²⁰⁹ is an apocalyptic number.

It is an amenable number.

387209 is a deficient number, since it is larger than the sum of its proper divisors (22795).

387209 is a wasteful number, since it uses less digits than its factorization.

387209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22794.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 387209 is about 622.2611991760. The cubic root of 387209 is about 72.8867324567.

The spelling of 387209 in words is "three hundred eighty-seven thousand, two hundred nine".