1381209 has 4 divisors (see below), whose sum is σ = 1841616. Its totient is φ = 920804.

The previous prime is 1381207. The next prime is 1381213. The reversal of 1381209 is 9021831.

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 1381209 - 2¹ = 1381207 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (1381207) 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, 230199 + ... + 230204.

It is an arithmetic number, because the mean of its divisors is an integer number (460404).

2^1381209 is an apocalyptic number.

It is an amenable number.

1381209 is a deficient number, since it is larger than the sum of its proper divisors (460407).

1381209 is an equidigital number, since it uses as much as digits as its factorization.

1381209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460406.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 1381209 is about 1175.2484843641. The cubic root of 1381209 is about 111.3661313086.

The spelling of 1381209 in words is "one million, three hundred eighty-one thousand, two hundred nine".