1389478009 has 4 divisors (see below), whose sum is σ = 1394004304. Its totient is φ = 1384951716.

The previous prime is 1389478007. The next prime is 1389478021. The reversal of 1389478009 is 9008749831.

It is a happy number.

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 1389478009 - 2¹ = 1389478007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1389478003) 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, 2262687 + ... + 2263300.

It is an arithmetic number, because the mean of its divisors is an integer number (348501076).

Almost surely, 2^1389478009 is an apocalyptic number.

It is an amenable number.

1389478009 is a deficient number, since it is larger than the sum of its proper divisors (4526295).

1389478009 is an equidigital number, since it uses as much as digits as its factorization.

1389478009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4526294.

The product of its (nonzero) digits is 435456, while the sum is 49.

The square root of 1389478009 is about 37275.7026627266. The cubic root of 1389478009 is about 1115.8793117369.

The spelling of 1389478009 in words is "one billion, three hundred eighty-nine million, four hundred seventy-eight thousand, nine".