21213100220 has 48 divisors (see below), whose sum is σ = 48201732768. Its totient is φ = 7795388160.

The previous prime is 21213100219. The next prime is 21213100231. The reversal of 21213100220 is 2200131212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21213100195 and 21213100204.

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, 138479 + ... + 248198.

It is an arithmetic number, because the mean of its divisors is an integer number (1004202766).

Almost surely, 2^21213100220 is an apocalyptic number.

21213100220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213100220 is an abundant number, since it is smaller than the sum of its proper divisors (26988632548).

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

21213100220 is a wasteful number, since it uses less digits than its factorization.

21213100220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386910 (or 386908 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21213100220 its reverse (2200131212), we get a palindrome (23413231432).

The spelling of 21213100220 in words is "twenty-one billion, two hundred thirteen million, one hundred thousand, two hundred twenty".