21102221020 has 24 divisors (see below), whose sum is σ = 44330273568. Its totient is φ = 8437915200.

The previous prime is 21102221011. The next prime is 21102221029. The reversal of 21102221020 is 2012220112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21102221011) and next prime (21102221029).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102221029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 127176 + ... + 241615.

It is an arithmetic number, because the mean of its divisors is an integer number (1847094732).

Almost surely, 2^21102221020 is an apocalyptic number.

21102221020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21102221020 is an abundant number, since it is smaller than the sum of its proper divisors (23228052548).

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

21102221020 is a wasteful number, since it uses less digits than its factorization.

21102221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371661 (or 371659 counting only the distinct ones).

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

Adding to 21102221020 its reverse (2012220112), we get a palindrome (23114441132).

The spelling of 21102221020 in words is "twenty-one billion, one hundred two million, two hundred twenty-one thousand, twenty".