21445344120 has 128 divisors (see below), whose sum is σ = 65205907200. Its totient is φ = 5641641984.

The previous prime is 21445344097. The next prime is 21445344133. The reversal of 21445344120 is 2144354412.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10148184 + ... + 10150296.

It is an arithmetic number, because the mean of its divisors is an integer number (509421150).

Almost surely, 2^21445344120 is an apocalyptic number.

21445344120 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 21445344120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32602953600).

21445344120 is an abundant number, since it is smaller than the sum of its proper divisors (43760563080).

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

21445344120 is a wasteful number, since it uses less digits than its factorization.

21445344120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3229 (or 3225 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 30.

Adding to 21445344120 its reverse (2144354412), we get a palindrome (23589698532).

The spelling of 21445344120 in words is "twenty-one billion, four hundred forty-five million, three hundred forty-four thousand, one hundred twenty".