21778372224 has 288 divisors, whose sum is σ = 73214015940. Its totient is φ = 6195732480.

The previous prime is 21778372219. The next prime is 21778372249. The reversal of 21778372224 is 42227387712.

It can be written as a sum of positive squares in 2 ways, for example, as 18018229824 + 3760142400 = 134232^2 + 61320^2 .

It is a tau number, because it is divible by the number of its divisors (288).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21778372224.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 15861202 + ... + 15862574.

Almost surely, 2^21778372224 is an apocalyptic number.

21778372224 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 21778372224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36607007970).

21778372224 is an abundant number, since it is smaller than the sum of its proper divisors (51435643716).

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

21778372224 is a wasteful number, since it uses less digits than its factorization.

21778372224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1688 (or 1666 counting only the distinct ones).

The product of its digits is 526848, while the sum is 45.

The spelling of 21778372224 in words is "twenty-one billion, seven hundred seventy-eight million, three hundred seventy-two thousand, two hundred twenty-four".