21220503220 has 96 divisors (see below), whose sum is σ = 51563651328. Its totient is φ = 7185395712.

The previous prime is 21220503167. The next prime is 21220503247. The reversal of 21220503220 is 2230502212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5285934 + ... + 5289946.

It is an arithmetic number, because the mean of its divisors is an integer number (537121368).

Almost surely, 2^21220503220 is an apocalyptic number.

21220503220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21220503220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25781825664).

21220503220 is an abundant number, since it is smaller than the sum of its proper divisors (30343148108).

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

21220503220 is a wasteful number, since it uses less digits than its factorization.

21220503220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4489 (or 4487 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The spelling of 21220503220 in words is "twenty-one billion, two hundred twenty million, five hundred three thousand, two hundred twenty".