1387209 has 8 divisors (see below), whose sum is σ = 1947040. Its totient is φ = 876096.

The previous prime is 1387207. The next prime is 1387213. The reversal of 1387209 is 9027831.

It is a happy number.

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

It is not a de Polignac number, because 1387209 - 2¹ = 1387207 is a prime.

It is a Duffinian number.

It is a Curzon number.

1387209 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387207) 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, 12112 + ... + 12225.

It is an arithmetic number, because the mean of its divisors is an integer number (243380).

2^1387209 is an apocalyptic number.

1387209 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1387209 is a deficient number, since it is larger than the sum of its proper divisors (559831).

1387209 is a wasteful number, since it uses less digits than its factorization.

1387209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24359.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 1387209 is about 1177.7983698410. The cubic root of 1387209 is about 111.5271572799.

It can be divided in two parts, 1387 and 209, that added together give a triangular number (1596 = T₅₆).

The spelling of 1387209 in words is "one million, three hundred eighty-seven thousand, two hundred nine".