1388689 has 4 divisors (see below), whose sum is σ = 1408320. Its totient is φ = 1369060.

The previous prime is 1388687. The next prime is 1388693. The reversal of 1388689 is 9868831.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9868831 = 7 ⋅1409833.

It is a cyclic number.

It is not a de Polignac number, because 1388689 - 2¹ = 1388687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1388687) 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, 9709 + ... + 9850.

It is an arithmetic number, because the mean of its divisors is an integer number (352080).

2^1388689 is an apocalyptic number.

It is an amenable number.

1388689 is a deficient number, since it is larger than the sum of its proper divisors (19631).

1388689 is an equidigital number, since it uses as much as digits as its factorization.

1388689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19630.

The product of its digits is 82944, while the sum is 43.

The square root of 1388689 is about 1178.4264932528. The cubic root of 1388689 is about 111.5668056019.

The spelling of 1388689 in words is "one million, three hundred eighty-eight thousand, six hundred eighty-nine".