28915128 has 72 divisors (see below), whose sum is σ = 86104200. Its totient is φ = 8759520.

The previous prime is 28915109. The next prime is 28915153. The reversal of 28915128 is 82151982.

It is a tau number, because it is divible by the number of its divisors (72).

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 = 28915092 and 28915101.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7053 + ... + 10371.

Almost surely, 2^28915128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28915128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43052100).

28915128 is an abundant number, since it is smaller than the sum of its proper divisors (57189072).

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

28915128 is a wasteful number, since it uses less digits than its factorization.

28915128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3353 (or 3335 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 28915128 is about 5377.2788657461. The cubic root of 28915128 is about 306.9316728402.

The spelling of 28915128 in words is "twenty-eight million, nine hundred fifteen thousand, one hundred twenty-eight".