21513123232 has 48 divisors (see below), whose sum is σ = 44213323392. Its totient is φ = 10284721920.

The previous prime is 21513123193. The next prime is 21513123241. The reversal of 21513123232 is 23232131512.

It is a junction number, because it is equal to n+sod(n) for n = 21513123197 and 21513123206.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2584357 + ... + 2592667.

It is an arithmetic number, because the mean of its divisors is an integer number (921110904).

Almost surely, 2^21513123232 is an apocalyptic number.

It is an amenable number.

21513123232 is an abundant number, since it is smaller than the sum of its proper divisors (22700200160).

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

21513123232 is a wasteful number, since it uses less digits than its factorization.

21513123232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11861 (or 11853 counting only the distinct ones).

The product of its digits is 2160, while the sum is 25.

Adding to 21513123232 its reverse (23232131512), we get a palindrome (44745254744).

The spelling of 21513123232 in words is "twenty-one billion, five hundred thirteen million, one hundred twenty-three thousand, two hundred thirty-two".