1389728 has 24 divisors (see below), whose sum is σ = 2764692. Its totient is φ = 687616.

The previous prime is 1389727. The next prime is 1389749. The reversal of 1389728 is 8279831.

It can be written as a sum of positive squares in 2 ways, for example, as 1317904 + 71824 = 1148^2 + 268^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1389691 and 1389700.

It is not an unprimeable number, because it can be changed into a prime (1389727) 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, 4226 + ... + 4542.

2^1389728 is an apocalyptic number.

It is an amenable number.

1389728 is a deficient number, since it is larger than the sum of its proper divisors (1374964).

1389728 is a wasteful number, since it uses less digits than its factorization.

1389728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 464 (or 456 counting only the distinct ones).

The product of its digits is 24192, while the sum is 38.

The square root of 1389728 is about 1178.8672529170. The cubic root of 1389728 is about 111.5946229686.

The spelling of 1389728 in words is "one million, three hundred eighty-nine thousand, seven hundred twenty-eight".