1388909 has 4 divisors (see below), whose sum is σ = 1411740. Its totient is φ = 1366080.

The previous prime is 1388887. The next prime is 1388927. The reversal of 1388909 is 9098831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9098831 = 7 ⋅1299833.

It can be written as a sum of positive squares in 2 ways, for example, as 31684 + 1357225 = 178^2 + 1165^2 .

It is a cyclic number.

It is not a de Polignac number, because 1388909 - 2¹² = 1384813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388969) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 11324 + ... + 11445.

It is an arithmetic number, because the mean of its divisors is an integer number (352935).

2^1388909 is an apocalyptic number.

It is an amenable number.

1388909 is a deficient number, since it is larger than the sum of its proper divisors (22831).

1388909 is an equidigital number, since it uses as much as digits as its factorization.

1388909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22830.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 1388909 is about 1178.5198343685. The cubic root of 1388909 is about 111.5726968660.

The spelling of 1388909 in words is "one million, three hundred eighty-eight thousand, nine hundred nine".