21202212220 has 192 divisors, whose sum is σ = 53038540800. Its totient is φ = 6970309632.

The previous prime is 21202212203. The next prime is 21202212257. The reversal of 21202212220 is 2221220212.

It is a super-3 number, since 3×21202212220³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21202212194 and 21202212203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 106543681 + ... + 106543879.

It is an arithmetic number, because the mean of its divisors is an integer number (276242400).

Almost surely, 2^21202212220 is an apocalyptic number.

21202212220 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 21202212220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26519270400).

21202212220 is an abundant number, since it is smaller than the sum of its proper divisors (31836328580).

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

21202212220 is a wasteful number, since it uses less digits than its factorization.

21202212220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524 (or 522 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21202212220 its reverse (2221220212), we get a palindrome (23423432432).

The spelling of 21202212220 in words is "twenty-one billion, two hundred two million, two hundred twelve thousand, two hundred twenty".