21224253072 has 40 divisors (see below), whose sum is σ = 59813805600. Its totient is φ = 6431591680.

The previous prime is 21224253059. The next prime is 21224253073. The reversal of 21224253072 is 27035242212.

It is not an unprimeable number, because it can be changed into a prime (21224253073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20098197 + ... + 20099252.

It is an arithmetic number, because the mean of its divisors is an integer number (1495345140).

Almost surely, 2^21224253072 is an apocalyptic number.

21224253072 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21224253072 is an abundant number, since it is smaller than the sum of its proper divisors (38589552528).

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

21224253072 is a wasteful number, since it uses less digits than its factorization.

21224253072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40197471 (or 40197465 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 30.

Adding to 21224253072 its reverse (27035242212), we get a palindrome (48259495284).

The spelling of 21224253072 in words is "twenty-one billion, two hundred twenty-four million, two hundred fifty-three thousand, seventy-two".