21878578224 has 100 divisors (see below), whose sum is σ = 64086195096. Its totient is φ = 7204958208.

The previous prime is 21878578217. The next prime is 21878578277. The reversal of 21878578224 is 42287587812.

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

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 19 ways as a sum of consecutive naturals, for example, 5872 + ... + 209264.

Almost surely, 2^21878578224 is an apocalyptic number.

21878578224 is a gapful number since it is divisible by the number (24) 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 21878578224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32043097548).

21878578224 is an abundant number, since it is smaller than the sum of its proper divisors (42207616872).

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

21878578224 is a wasteful number, since it uses less digits than its factorization.

21878578224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203496 (or 203481 counting only the distinct ones).

The product of its digits is 4014080, while the sum is 54.

The spelling of 21878578224 in words is "twenty-one billion, eight hundred seventy-eight million, five hundred seventy-eight thousand, two hundred twenty-four".