28385786440 has 128 divisors (see below), whose sum is σ = 73424361600. Its totient is φ = 9767761920.

The previous prime is 28385786413. The next prime is 28385786479. The reversal of 28385786440 is 4468758382.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11477044 + ... + 11479516.

It is an arithmetic number, because the mean of its divisors is an integer number (573627825).

Almost surely, 2^28385786440 is an apocalyptic number.

28385786440 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 28385786440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36712180800).

28385786440 is an abundant number, since it is smaller than the sum of its proper divisors (45038575160).

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

28385786440 is a wasteful number, since it uses less digits than its factorization.

28385786440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3887 (or 3883 counting only the distinct ones).

The product of its (nonzero) digits is 10321920, while the sum is 55.

The spelling of 28385786440 in words is "twenty-eight billion, three hundred eighty-five million, seven hundred eighty-six thousand, four hundred forty".