21011202220 has 48 divisors (see below), whose sum is σ = 44607024000. Its totient is φ = 8312864000.

The previous prime is 21011202209. The next prime is 21011202221. The reversal of 21011202220 is 2220211012.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21011202220.

It is not an unprimeable number, because it can be changed into a prime (21011202221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 697470 + ... + 726970.

It is an arithmetic number, because the mean of its divisors is an integer number (929313000).

Almost surely, 2^21011202220 is an apocalyptic number.

21011202220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011202220 is an abundant number, since it is smaller than the sum of its proper divisors (23595821780).

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

21011202220 is a wasteful number, since it uses less digits than its factorization.

21011202220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29898 (or 29896 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21011202220 its reverse (2220211012), we get a palindrome (23231413232).

The spelling of 21011202220 in words is "twenty-one billion, eleven million, two hundred two thousand, two hundred twenty".