28988505 has 48 divisors (see below), whose sum is σ = 61850880. Its totient is φ = 12230784.

The previous prime is 28988489. The next prime is 28988507. The reversal of 28988505 is 50588982.

It is not a de Polignac number, because 28988505 - 2⁴ = 28988489 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28988507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 556 + ... + 7634.

It is an arithmetic number, because the mean of its divisors is an integer number (1288560).

Almost surely, 2^28988505 is an apocalyptic number.

It is an amenable number.

28988505 is an abundant number, since it is smaller than the sum of its proper divisors (32862375).

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

28988505 is a wasteful number, since it uses less digits than its factorization.

28988505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7110 (or 7107 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 45.

The square root of 28988505 is about 5384.0974173950. The cubic root of 28988505 is about 307.1910837765.

The spelling of 28988505 in words is "twenty-eight million, nine hundred eighty-eight thousand, five hundred five".