28871808 has 128 divisors (see below), whose sum is σ = 91653120. Its totient is φ = 7873536.

The previous prime is 28871789. The next prime is 28871809. The reversal of 28871808 is 80817882.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 28871808.

It is not an unprimeable number, because it can be changed into a prime (28871809) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61591 + ... + 62057.

It is an arithmetic number, because the mean of its divisors is an integer number (716040).

Almost surely, 2^28871808 is an apocalyptic number.

28871808 is a gapful number since it is divisible by the number (28) 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 28871808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45826560).

28871808 is an abundant number, since it is smaller than the sum of its proper divisors (62781312).

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

28871808 is a wasteful number, since it uses less digits than its factorization.

28871808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514 (or 502 counting only the distinct ones).

The product of its (nonzero) digits is 57344, while the sum is 42.

The square root of 28871808 is about 5373.2492962825. The cubic root of 28871808 is about 306.7783168338.

The spelling of 28871808 in words is "twenty-eight million, eight hundred seventy-one thousand, eight hundred eight".