1389639 has 4 divisors (see below), whose sum is σ = 1852856. Its totient is φ = 926424.

The previous prime is 1389629. The next prime is 1389643. The reversal of 1389639 is 9369831.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1389639 - 2⁴ = 1389623 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1389597 and 1389606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1389629) 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, 231604 + ... + 231609.

It is an arithmetic number, because the mean of its divisors is an integer number (463214).

2^1389639 is an apocalyptic number.

1389639 is a deficient number, since it is larger than the sum of its proper divisors (463217).

1389639 is an equidigital number, since it uses as much as digits as its factorization.

1389639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463216.

The product of its digits is 34992, while the sum is 39.

The square root of 1389639 is about 1178.8295042117. The cubic root of 1389639 is about 111.5922406959.

The spelling of 1389639 in words is "one million, three hundred eighty-nine thousand, six hundred thirty-nine".