1389128832 has 384 divisors, whose sum is σ = 5144227200. Its totient is φ = 365783040.

The previous prime is 1389128801. The next prime is 1389128843. The reversal of 1389128832 is 2388219831.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2201157 + ... + 2201787.

It is an arithmetic number, because the mean of its divisors is an integer number (13396425).

Almost surely, 2^1389128832 is an apocalyptic number.

1389128832 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1389128832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2572113600).

1389128832 is an abundant number, since it is smaller than the sum of its proper divisors (3755098368).

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

1389128832 is a wasteful number, since it uses less digits than its factorization.

1389128832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681 (or 656 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 1389128832 is about 37271.0186606162. The cubic root of 1389128832 is about 1115.7858301006.

Subtracting 1389128832 from its reverse (2388219831), we obtain a palindrome (999090999).

The spelling of 1389128832 in words is "one billion, three hundred eighty-nine million, one hundred twenty-eight thousand, eight hundred thirty-two".