1388664 has 40 divisors (see below), whose sum is σ = 3891360. Its totient is φ = 462672.

The previous prime is 1388659. The next prime is 1388669. The reversal of 1388664 is 4668831.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1388659) and next prime (1388669).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388669) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 424 + ... + 1719.

It is an arithmetic number, because the mean of its divisors is an integer number (97284).

2^1388664 is an apocalyptic number.

It is an amenable number.

1388664 is an abundant number, since it is smaller than the sum of its proper divisors (2502696).

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

1388664 is a wasteful number, since it uses less digits than its factorization.

1388664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2161 (or 2148 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 1388664 is about 1178.4158858400. The cubic root of 1388664 is about 111.5661361007.

The spelling of 1388664 in words is "one million, three hundred eighty-eight thousand, six hundred sixty-four".