1389726208 has 60 divisors (see below), whose sum is σ = 3006950958. Its totient is φ = 641372160.

The previous prime is 1389726199. The next prime is 1389726257. The reversal of 1389726208 is 8026279831.

It can be written as a sum of positive squares in 3 ways, for example, as 257538304 + 1132187904 = 16048^2 + 33648^2 .

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 78498 + ... + 94558.

Almost surely, 2^1389726208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1389726208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1503475479).

1389726208 is an abundant number, since it is smaller than the sum of its proper divisors (1617224750).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1389726208 is an equidigital number, since it uses as much as digits as its factorization.

1389726208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16105 (or 16076 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 1389726208 is about 37279.0317470827. The cubic root of 1389726208 is about 1115.9457500297.

The spelling of 1389726208 in words is "one billion, three hundred eighty-nine million, seven hundred twenty-six thousand, two hundred eight".