28981800 has 120 divisors (see below), whose sum is σ = 100714350. Its totient is φ = 7724160.

The previous prime is 28981769. The next prime is 28981819. The reversal of 28981800 is 818982.

It can be written as a sum of positive squares in 3 ways, for example, as 27060804 + 1920996 = 5202^2 + 1386^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 15306 + ... + 17094.

Almost surely, 2^28981800 is an apocalyptic number.

28981800 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 28981800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50357175).

28981800 is an abundant number, since it is smaller than the sum of its proper divisors (71732550).

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

28981800 is a wasteful number, since it uses less digits than its factorization.

28981800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1817 (or 1799 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 28981800 is about 5383.4747143457. The cubic root of 28981800 is about 307.1673976632.

The spelling of 28981800 in words is "twenty-eight million, nine hundred eighty-one thousand, eight hundred".