21449538252 has 18 divisors (see below), whose sum is σ = 54219666228. Its totient is φ = 7149846072.

The previous prime is 21449538251. The next prime is 21449538269. The reversal of 21449538252 is 25283594412.

21449538252 is a `hidden beast` number, since 21 + 4 + 49 + 538 + 2 + 52 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×21449538252² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21449538198 and 21449538207.

It is not an unprimeable number, because it can be changed into a prime (21449538251) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 297910218 + ... + 297910289.

Almost surely, 2^21449538252 is an apocalyptic number.

It is an amenable number.

21449538252 is an abundant number, since it is smaller than the sum of its proper divisors (32770127976).

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

21449538252 is a wasteful number, since it uses less digits than its factorization.

21449538252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 595820517 (or 595820512 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The spelling of 21449538252 in words is "twenty-one billion, four hundred forty-nine million, five hundred thirty-eight thousand, two hundred fifty-two".