1389840 has 40 divisors (see below), whose sum is σ = 4309248. Its totient is φ = 370560.

The previous prime is 1389833. The next prime is 1389841. The reversal of 1389840 is 489831.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1389841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2656 + ... + 3135.

2^1389840 is an apocalyptic number.

1389840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1389840 is an abundant number, since it is smaller than the sum of its proper divisors (2919408).

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

1389840 is a wasteful number, since it uses less digits than its factorization.

1389840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5807 (or 5801 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 1389840 is about 1178.9147551880. The cubic root of 1389840 is about 111.5976207404.

Subtracting from 1389840 its reverse (489831), we obtain a palindrome (900009).

The spelling of 1389840 in words is "one million, three hundred eighty-nine thousand, eight hundred forty".