21010011220 has 24 divisors (see below), whose sum is σ = 48132026208. Its totient is φ = 7640004000.

The previous prime is 21010011203. The next prime is 21010011223. The reversal of 21010011220 is 2211001012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21010011197 and 21010011206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010011223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47749806 + ... + 47750245.

It is an arithmetic number, because the mean of its divisors is an integer number (2005501092).

Almost surely, 2^21010011220 is an apocalyptic number.

21010011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21010011220 is an abundant number, since it is smaller than the sum of its proper divisors (27122014988).

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

21010011220 is a wasteful number, since it uses less digits than its factorization.

21010011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95500071 (or 95500069 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21010011220 its reverse (2211001012), we get a palindrome (23221012232).

The spelling of 21010011220 in words is "twenty-one billion, ten million, eleven thousand, two hundred twenty".