21244523412 has 96 divisors (see below), whose sum is σ = 58952678400. Its totient is φ = 5828159232.

The previous prime is 21244523389. The next prime is 21244523423. The reversal of 21244523412 is 21432544212.

It is a happy number.

It is a super-2 number, since 2×21244523412² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21244523412.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 163264 + ... + 262952.

It is an arithmetic number, because the mean of its divisors is an integer number (614090400).

Almost surely, 2^21244523412 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21244523412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29476339200).

21244523412 is an abundant number, since it is smaller than the sum of its proper divisors (37708154988).

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

21244523412 is a wasteful number, since it uses less digits than its factorization.

21244523412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99805 (or 99803 counting only the distinct ones).

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

It can be divided in two parts, 2124 and 4523412, that added together give a triangular number (4525536 = T₃₀₀₈).

The spelling of 21244523412 in words is "twenty-one billion, two hundred forty-four million, five hundred twenty-three thousand, four hundred twelve".