21222451224 has 128 divisors (see below), whose sum is σ = 64684267200. Its totient is φ = 6406732800.

The previous prime is 21222451193. The next prime is 21222451241. The reversal of 21222451224 is 42215422212.

21222451224 is a `hidden beast` number, since 2 + 122 + 2 + 4 + 512 + 24 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 77524 + ... + 220124.

Almost surely, 2^21222451224 is an apocalyptic number.

21222451224 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 21222451224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32342133600).

21222451224 is an abundant number, since it is smaller than the sum of its proper divisors (43461815976).

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

21222451224 is a wasteful number, since it uses less digits than its factorization.

21222451224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142682 (or 142672 counting only the distinct ones).

The product of its digits is 5120, while the sum is 27.

Adding to 21222451224 its reverse (42215422212), we get a palindrome (63437873436).

The spelling of 21222451224 in words is "twenty-one billion, two hundred twenty-two million, four hundred fifty-one thousand, two hundred twenty-four".