28215000 has 320 divisors, whose sum is σ = 112464000. Its totient is φ = 6480000.

The previous prime is 28214987. The next prime is 28215007. The reversal of 28215000 is 51282.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28215007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1484991 + ... + 1485009.

It is an arithmetic number, because the mean of its divisors is an integer number (351450).

Almost surely, 2^28215000 is an apocalyptic number.

28215000 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 28215000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56232000).

28215000 is an abundant number, since it is smaller than the sum of its proper divisors (84249000).

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

28215000 is a wasteful number, since it uses less digits than its factorization.

28215000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65 (or 40 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 28215000 is about 5311.7793628877. The cubic root of 28215000 is about 304.4341384892.

Adding to 28215000 its reverse (51282), we get a palindrome (28266282).

The spelling of 28215000 in words is "twenty-eight million, two hundred fifteen thousand".