21231210204224 has 56 divisors (see below), whose sum is σ = 42681259580160. Its totient is φ = 10476985918464.

The previous prime is 21231210204179. The next prime is 21231210204241. The reversal of 21231210204224 is 42240201213212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21231210204193 and 21231210204202.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11654477 + ... + 13352499.

Almost surely, 2^{21231210204224} 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 21231210204224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21340629790080).

21231210204224 is an abundant number, since it is smaller than the sum of its proper divisors (21450049375936).

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

21231210204224 is a wasteful number, since it uses less digits than its factorization.

21231210204224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1700587 (or 1700577 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

Adding to 21231210204224 its reverse (42240201213212), we get a palindrome (63471411417436).

The spelling of 21231210204224 in words is "twenty-one trillion, two hundred thirty-one billion, two hundred ten million, two hundred four thousand, two hundred twenty-four".