21530405532 has 24 divisors (see below), whose sum is σ = 50735017872. Its totient is φ = 7105744000.

The previous prime is 21530405527. The next prime is 21530405621. The reversal of 21530405532 is 23550403512.

It is a self number, because there is not a number n which added to its sum of digits gives 21530405532.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8880969 + ... + 8883392.

It is an arithmetic number, because the mean of its divisors is an integer number (2113959078).

Almost surely, 2^21530405532 is an apocalyptic number.

It is an amenable number.

21530405532 is an abundant number, since it is smaller than the sum of its proper divisors (29204612340).

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

21530405532 is a wasteful number, since it uses less digits than its factorization.

21530405532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17764469 (or 17764467 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 30.

The spelling of 21530405532 in words is "twenty-one billion, five hundred thirty million, four hundred five thousand, five hundred thirty-two".