28478807820 has 216 divisors, whose sum is σ = 92610580608. Its totient is φ = 7348320000.

The previous prime is 28478807801. The next prime is 28478807827. The reversal of 28478807820 is 2870887482.

28478807820 is a `hidden beast` number, since 2 + 8 + 478 + 80 + 78 + 20 = 666.

It is a super-2 number, since 2×28478807820² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (28478807827) 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, 4064320 + ... + 4071320.

It is an arithmetic number, because the mean of its divisors is an integer number (428752688).

Almost surely, 2^28478807820 is an apocalyptic number.

28478807820 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 28478807820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46305290304).

28478807820 is an abundant number, since it is smaller than the sum of its proper divisors (64131772788).

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

28478807820 is an equidigital number, since it uses as much as digits as its factorization.

28478807820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7065 (or 7042 counting only the distinct ones).

The product of its (nonzero) digits is 3211264, while the sum is 54.

The spelling of 28478807820 in words is "twenty-eight billion, four hundred seventy-eight million, eight hundred seven thousand, eight hundred twenty".