1387728 has 60 divisors (see below), whose sum is σ = 4062240. Its totient is φ = 441408.

The previous prime is 1387721. The next prime is 1387733. The reversal of 1387728 is 8277831.

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

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 1387692 and 1387701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3103 + ... + 3521.

It is an arithmetic number, because the mean of its divisors is an integer number (67704).

2^1387728 is an apocalyptic number.

1387728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1387728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2031120).

1387728 is an abundant number, since it is smaller than the sum of its proper divisors (2674512).

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

1387728 is a wasteful number, since it uses less digits than its factorization.

1387728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456 (or 447 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 1387728 is about 1178.0186755735. The cubic root of 1387728 is about 111.5410641912.

The spelling of 1387728 in words is "one million, three hundred eighty-seven thousand, seven hundred twenty-eight".