16138728 has 24 divisors (see below), whose sum is σ = 43709250. Its totient is φ = 5379552.

The previous prime is 16138721. The next prime is 16138739. The reversal of 16138728 is 82783161.

16138728 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 9998244 + 6140484 = 3162^2 + 2478^2 .

It is a tau number, because it is divible by the number of its divisors (24).

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 = 16138692 and 16138701.

It is not an unprimeable number, because it can be changed into a prime (16138721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 112003 + ... + 112146.

Almost surely, 2^16138728 is an apocalyptic number.

16138728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

16138728 is an abundant number, since it is smaller than the sum of its proper divisors (27570522).

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

16138728 is a wasteful number, since it uses less digits than its factorization.

16138728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224161 (or 224154 counting only the distinct ones).

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

The square root of 16138728 is about 4017.3035732939. The cubic root of 16138728 is about 252.7103915838.

The spelling of 16138728 in words is "sixteen million, one hundred thirty-eight thousand, seven hundred twenty-eight".