21505444450512 has 120 divisors (see below), whose sum is σ = 61079859597120. Its totient is φ = 6515257267200.

The previous prime is 21505444450489. The next prime is 21505444450531.

21505444450512 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24195189 + ... + 25068267.

It is an arithmetic number, because the mean of its divisors is an integer number (508998829976).

Almost surely, 2^{21505444450512} is an apocalyptic number.

21505444450512 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 21505444450512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30539929798560).

21505444450512 is an abundant number, since it is smaller than the sum of its proper divisors (39574415146608).

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

21505444450512 is a wasteful number, since it uses less digits than its factorization.

21505444450512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 877353 (or 877336 counting only the distinct ones).

The product of its (nonzero) digits is 640000, while the sum is 42.

The spelling of 21505444450512 in words is "twenty-one trillion, five hundred five billion, four hundred forty-four million, four hundred fifty thousand, five hundred twelve".