21530013152 has 48 divisors (see below), whose sum is σ = 43563299472. Its totient is φ = 10468039680.

The previous prime is 21530013149. The next prime is 21530013157. The reversal of 21530013152 is 25131003512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530013157) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 376058 + ... + 429510.

It is an arithmetic number, because the mean of its divisors is an integer number (907568739).

Almost surely, 2^21530013152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21530013152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21781649736).

21530013152 is an abundant number, since it is smaller than the sum of its proper divisors (22033286320).

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

21530013152 is a wasteful number, since it uses less digits than its factorization.

21530013152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53811 (or 53803 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 23.

Adding to 21530013152 its reverse (25131003512), we get a palindrome (46661016664).

The spelling of 21530013152 in words is "twenty-one billion, five hundred thirty million, thirteen thousand, one hundred fifty-two".