21530013200 has 30 divisors (see below), whose sum is σ = 51725857674. Its totient is φ = 8612005120.

The previous prime is 21530013187. The next prime is 21530013223. The reversal of 21530013200 is 231003512.

It can be written as a sum of positive squares in 3 ways, for example, as 218684944 + 21311328256 = 14788^2 + 145984^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26912117 + ... + 26912916.

Almost surely, 2^21530013200 is an apocalyptic number.

21530013200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21530013200 is an abundant number, since it is smaller than the sum of its proper divisors (30195844474).

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

21530013200 is a wasteful number, since it uses less digits than its factorization.

21530013200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53825051 (or 53825040 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 17.

Adding to 21530013200 its reverse (231003512), we get a palindrome (21761016712).

The spelling of 21530013200 in words is "twenty-one billion, five hundred thirty million, thirteen thousand, two hundred".