21243544534212 has 432 divisors, whose sum is σ = 69954907684032. Its totient is φ = 4955689589760.

The previous prime is 21243544534193. The next prime is 21243544534213.

21243544534212 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (21243544534213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 40181778 + ... + 40707030.

It is an arithmetic number, because the mean of its divisors is an integer number (161932656676).

Almost surely, 2^{21243544534212} is an apocalyptic number.

21243544534212 is a gapful number since it is divisible by the number (22) 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 21243544534212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34977453842016).

21243544534212 is an abundant number, since it is smaller than the sum of its proper divisors (48711363149820).

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

21243544534212 is a wasteful number, since it uses less digits than its factorization.

21243544534212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525348 (or 525326 counting only the distinct ones).

The product of its digits is 921600, while the sum is 42.

It can be divided in two parts, 2124354 and 4534212, that added together give a palindrome (6658566).

The spelling of 21243544534212 in words is "twenty-one trillion, two hundred forty-three billion, five hundred forty-four million, five hundred thirty-four thousand, two hundred twelve".