28101800 has 48 divisors (see below), whose sum is σ = 66290400. Its totient is φ = 11076800.

The previous prime is 28101797. The next prime is 28101803. The reversal of 28101800 is 810182.

It is an interprime number because it is at equal distance from previous prime (28101797) and next prime (28101803).

It is a super-2 number, since 2×28101800² = 1579422326480000, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (28101803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13211 + ... + 15189.

It is an arithmetic number, because the mean of its divisors is an integer number (1381050).

Almost surely, 2^28101800 is an apocalyptic number.

28101800 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 28101800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33145200).

28101800 is an abundant number, since it is smaller than the sum of its proper divisors (38188600).

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

28101800 is a wasteful number, since it uses less digits than its factorization.

28101800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2066 (or 2057 counting only the distinct ones).

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

The square root of 28101800 is about 5301.1130906631. The cubic root of 28101800 is about 304.0264577619.

Adding to 28101800 its reverse (810182), we get a palindrome (28911982).

The spelling of 28101800 in words is "twenty-eight million, one hundred one thousand, eight hundred".