1318321728 has 168 divisors, whose sum is σ = 3971275776. Its totient is φ = 417331200.

The previous prime is 1318321703. The next prime is 1318321769. The reversal of 1318321728 is 8271238131.

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

It is a junction number, because it is equal to n+sod(n) for n = 1318321692 and 1318321701.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2530108 + ... + 2530628.

Almost surely, 2^1318321728 is an apocalyptic number.

1318321728 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 1318321728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1985637888).

1318321728 is an abundant number, since it is smaller than the sum of its proper divisors (2652954048).

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

1318321728 is a wasteful number, since it uses less digits than its factorization.

1318321728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 753 (or 740 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 1318321728 is about 36308.7004449347. The cubic root of 1318321728 is about 1096.4962144687.

Adding to 1318321728 its reverse (8271238131), we get a palindrome (9589559859).

The spelling of 1318321728 in words is "one billion, three hundred eighteen million, three hundred twenty-one thousand, seven hundred twenty-eight".