28811000 has 64 divisors (see below), whose sum is σ = 68964480. Its totient is φ = 11260800.

The previous prime is 28810993. The next prime is 28811023. The reversal of 28811000 is 11882.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46694 + ... + 47306.

It is an arithmetic number, because the mean of its divisors is an integer number (1077570).

Almost surely, 2^28811000 is an apocalyptic number.

28811000 is a gapful number since it is divisible by the number (20) 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 28811000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34482240).

28811000 is an abundant number, since it is smaller than the sum of its proper divisors (40153480).

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

28811000 is a wasteful number, since it uses less digits than its factorization.

28811000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681 (or 667 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 28811000 is about 5367.5879126475. The cubic root of 28811000 is about 306.5627930074.

Adding to 28811000 its reverse (11882), we get a palindrome (28822882).

The spelling of 28811000 in words is "twenty-eight million, eight hundred eleven thousand".