21321322224 has 80 divisors (see below), whose sum is σ = 56602127232. Its totient is φ = 6910942464.

The previous prime is 21321322219. The next prime is 21321322241. The reversal of 21321322224 is 42222312312.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21321322194 and 21321322203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4975987 + ... + 4980269.

Almost surely, 2^21321322224 is an apocalyptic number.

21321322224 is a gapful number since it is divisible by the number (24) 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 21321322224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28301063616).

21321322224 is an abundant number, since it is smaller than the sum of its proper divisors (35280805008).

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

21321322224 is a wasteful number, since it uses less digits than its factorization.

21321322224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7134 (or 7128 counting only the distinct ones).

The product of its digits is 2304, while the sum is 24.

Adding to 21321322224 its reverse (42222312312), we get a palindrome (63543634536).

The spelling of 21321322224 in words is "twenty-one billion, three hundred twenty-one million, three hundred twenty-two thousand, two hundred twenty-four".