28218284640 has 432 divisors, whose sum is σ = 120637088208. Its totient is φ = 5953554432.

The previous prime is 28218284623. The next prime is 28218284641. The reversal of 28218284640 is 4648281282.

28218284640 is a `hidden beast` number, since 2 + 8 + 2 + 182 + 8 + 464 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28218284641) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 901899 + ... + 932661.

It is an arithmetic number, because the mean of its divisors is an integer number (279252519).

Almost surely, 2^28218284640 is an apocalyptic number.

28218284640 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 28218284640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60318544104).

28218284640 is an abundant number, since it is smaller than the sum of its proper divisors (92418803568).

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

28218284640 is a wasteful number, since it uses less digits than its factorization.

28218284640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30811 (or 30793 counting only the distinct ones).

The product of its (nonzero) digits is 393216, while the sum is 45.

The spelling of 28218284640 in words is "twenty-eight billion, two hundred eighteen million, two hundred eighty-four thousand, six hundred forty".