21517225072 has 40 divisors (see below), whose sum is σ = 47826510336. Its totient is φ = 9186591936.

The previous prime is 21517225049. The next prime is 21517225141. The reversal of 21517225072 is 27052271512.

It is a congruent number.

It is an unprimeable number.

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, 335788 + ... + 394699.

Almost surely, 2^21517225072 is an apocalyptic number.

It is an amenable number.

21517225072 is an abundant number, since it is smaller than the sum of its proper divisors (26309285264).

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

21517225072 is a wasteful number, since it uses less digits than its factorization.

21517225072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730765 (or 730759 counting only the distinct ones).

The product of its (nonzero) digits is 19600, while the sum is 34.

Adding to 21517225072 its reverse (27052271512), we get a palindrome (48569496584).

The spelling of 21517225072 in words is "twenty-one billion, five hundred seventeen million, two hundred twenty-five thousand, seventy-two".