1380209 has 4 divisors (see below), whose sum is σ = 1397760. Its totient is φ = 1362660.

The previous prime is 1380199. The next prime is 1380221. The reversal of 1380209 is 9020831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1380209 - 2⁸ = 1379953 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1380259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8657 + ... + 8814.

It is an arithmetic number, because the mean of its divisors is an integer number (349440).

2^1380209 is an apocalyptic number.

It is an amenable number.

1380209 is a deficient number, since it is larger than the sum of its proper divisors (17551).

1380209 is an equidigital number, since it uses as much as digits as its factorization.

1380209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17550.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1380209 is about 1174.8229653867. The cubic root of 1380209 is about 111.3392483341.

It can be divided in two parts, 1380 and 209, that multiplied together give a triangular number (288420 = T₇₅₉).

The spelling of 1380209 in words is "one million, three hundred eighty thousand, two hundred nine".