21312242020240 has 80 divisors (see below), whose sum is σ = 49913427211200. Its totient is φ = 8462552034816.

The previous prime is 21312242020229. The next prime is 21312242020247. The reversal of 21312242020240 is 4202024221312.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (21312242020247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 96288739 + ... + 96509821.

It is an arithmetic number, because the mean of its divisors is an integer number (623917840140).

Almost surely, 2^{21312242020240} is an apocalyptic number.

21312242020240 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 21312242020240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24956713605600).

21312242020240 is an abundant number, since it is smaller than the sum of its proper divisors (28601185190960).

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

21312242020240 is a wasteful number, since it uses less digits than its factorization.

21312242020240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229904 (or 229898 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21312242020240 its reverse (4202024221312), we get a palindrome (25514266241552).

The spelling of 21312242020240 in words is "twenty-one trillion, three hundred twelve billion, two hundred forty-two million, twenty thousand, two hundred forty".