21313331220 has 48 divisors (see below), whose sum is σ = 59766114240. Its totient is φ = 5675099136.

The previous prime is 21313331213. The next prime is 21313331243. The reversal of 21313331220 is 2213331312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 223530 + ... + 304289.

It is an arithmetic number, because the mean of its divisors is an integer number (1245127380).

Almost surely, 2^21313331220 is an apocalyptic number.

21313331220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21313331220 is an abundant number, since it is smaller than the sum of its proper divisors (38452783020).

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

21313331220 is a wasteful number, since it uses less digits than its factorization.

21313331220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528504 (or 528502 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21313331220 its reverse (2213331312), we get a palindrome (23526662532).

The spelling of 21313331220 in words is "twenty-one billion, three hundred thirteen million, three hundred thirty-one thousand, two hundred twenty".