21513332320 has 24 divisors (see below), whose sum is σ = 50825247984. Its totient is φ = 8605332864.

The previous prime is 21513332263. The next prime is 21513332333. The reversal of 21513332320 is 2323331512.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67229004 + ... + 67229323.

It is an arithmetic number, because the mean of its divisors is an integer number (2117718666).

Almost surely, 2^21513332320 is an apocalyptic number.

21513332320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21513332320 is an abundant number, since it is smaller than the sum of its proper divisors (29311915664).

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

21513332320 is a wasteful number, since it uses less digits than its factorization.

21513332320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134458342 (or 134458334 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 25.

Adding to 21513332320 its reverse (2323331512), we get a palindrome (23836663832).

The spelling of 21513332320 in words is "twenty-one billion, five hundred thirteen million, three hundred thirty-two thousand, three hundred twenty".