15121728 has 70 divisors (see below), whose sum is σ = 44840906. Its totient is φ = 5038848.

The previous prime is 15121709. The next prime is 15121747. The reversal of 15121728 is 82712151.

15121728 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 is an interprime number because it is at equal distance from previous prime (15121709) and next prime (15121747).

It can be written as a sum of positive squares in only one way, i.e., 15116544 + 5184 = 3888^2 + 72^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3726 + ... + 6642.

Almost surely, 2^15121728 is an apocalyptic number.

15121728 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 15121728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22420453).

15121728 is an abundant number, since it is smaller than the sum of its proper divisors (29719178).

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

15121728 is an equidigital number, since it uses as much as digits as its factorization.

15121728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2941 (or 2922 counting only the distinct ones).

The product of its digits is 1120, while the sum is 27.

The square root of 15121728 is about 3888.6666095205. Note that the first 4 decimals coincide. The cubic root of 15121728 is about 247.2865377104.

Adding to 15121728 its reverse (82712151), we get a palindrome (97833879).

It can be divided in two parts, 1512 and 1728, that added together give a triangular number (3240 = T₈₀).

The spelling of 15121728 in words is "fifteen million, one hundred twenty-one thousand, seven hundred twenty-eight".