21020110110 has 96 divisors (see below), whose sum is σ = 56052453600. Its totient is φ = 5462360064.

The previous prime is 21020110091. The next prime is 21020110121. The reversal of 21020110110 is 1101102012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21020110092 and 21020110101.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 1731582 + ... + 1743678.

It is an arithmetic number, because the mean of its divisors is an integer number (583879725).

Almost surely, 2^21020110110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020110110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28026226800).

21020110110 is an abundant number, since it is smaller than the sum of its proper divisors (35032343490).

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

21020110110 is a wasteful number, since it uses less digits than its factorization.

21020110110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12602 (or 12599 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21020110110 its reverse (1101102012), we get a palindrome (22121212122).

The spelling of 21020110110 in words is "twenty-one billion, twenty million, one hundred ten thousand, one hundred ten".