1388840 has 16 divisors (see below), whose sum is σ = 3124980. Its totient is φ = 555520.

The previous prime is 1388837. The next prime is 1388873. The reversal of 1388840 is 488831.

It can be written as a sum of positive squares in 2 ways, for example, as 1387684 + 1156 = 1178^2 + 34^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1388797 and 1388806.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17321 + ... + 17400.

2^1388840 is an apocalyptic number.

1388840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1388840 is an abundant number, since it is smaller than the sum of its proper divisors (1736140).

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

1388840 is a wasteful number, since it uses less digits than its factorization.

1388840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34732 (or 34728 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 1388840 is about 1178.4905599961. The cubic root of 1388840 is about 111.5708492183.

Subtracting from 1388840 its reverse (488831), we obtain a palindrome (900009).

The spelling of 1388840 in words is "one million, three hundred eighty-eight thousand, eight hundred forty".