28217700 has 144 divisors (see below), whose sum is σ = 103743360. Its totient is φ = 6445440.

The previous prime is 28217669. The next prime is 28217701. The reversal of 28217700 is 771282.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (28217701) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 18154 + ... + 19646.

It is an arithmetic number, because the mean of its divisors is an integer number (720440).

Almost surely, 2^28217700 is an apocalyptic number.

28217700 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 28217700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51871680).

28217700 is an abundant number, since it is smaller than the sum of its proper divisors (75525660).

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

28217700 is a wasteful number, since it uses less digits than its factorization.

28217700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1523 (or 1510 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 28217700 is about 5312.0335089305. The cubic root of 28217700 is about 304.4438489973.

Adding to 28217700 its reverse (771282), we get a palindrome (28988982).

The spelling of 28217700 in words is "twenty-eight million, two hundred seventeen thousand, seven hundred".