21001102220 has 48 divisors (see below), whose sum is σ = 50438299968. Its totient is φ = 7195284480.

The previous prime is 21001102219. The next prime is 21001102247. The reversal of 21001102220 is 2220110012.

It is a happy 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, 148280 + ... + 252960.

It is an arithmetic number, because the mean of its divisors is an integer number (1050797916).

Almost surely, 2^21001102220 is an apocalyptic number.

21001102220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001102220 is an abundant number, since it is smaller than the sum of its proper divisors (29437197748).

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

21001102220 is a wasteful number, since it uses less digits than its factorization.

21001102220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106130 (or 106128 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21001102220 its reverse (2220110012), we get a palindrome (23221212232).

The spelling of 21001102220 in words is "twenty-one billion, one million, one hundred two thousand, two hundred twenty".