28218240 has 256 divisors, whose sum is σ = 105753600. Its totient is φ = 7096320.

The previous prime is 28218221. The next prime is 28218259. The reversal of 28218240 is 4281282.

It is an interprime number because it is at equal distance from previous prime (28218221) and next prime (28218259).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 397405 + ... + 397475.

It is an arithmetic number, because the mean of its divisors is an integer number (413100).

Almost surely, 2^28218240 is an apocalyptic number.

28218240 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 28218240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52876800).

28218240 is an abundant number, since it is smaller than the sum of its proper divisors (77535360).

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

28218240 is a wasteful number, since it uses less digits than its factorization.

28218240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 28218240 is about 5312.0843366799. The cubic root of 28218240 is about 304.4457910246.

The spelling of 28218240 in words is "twenty-eight million, two hundred eighteen thousand, two hundred forty".