21010211220 has 48 divisors (see below), whose sum is σ = 58845568320. Its totient is φ = 5601106176.

The previous prime is 21010211197. The next prime is 21010211227. The reversal of 21010211220 is 2211201012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21010211196 and 21010211205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010211227) 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, 166851 + ... + 264309.

It is an arithmetic number, because the mean of its divisors is an integer number (1225949340).

Almost surely, 2^21010211220 is an apocalyptic number.

21010211220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21010211220 is an abundant number, since it is smaller than the sum of its proper divisors (37835357100).

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

21010211220 is a wasteful number, since it uses less digits than its factorization.

21010211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101064 (or 101062 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21010211220 its reverse (2211201012), we get a palindrome (23221412232).

The spelling of 21010211220 in words is "twenty-one billion, ten million, two hundred eleven thousand, two hundred twenty".