21020020110 has 48 divisors (see below), whose sum is σ = 54668103984. Its totient is φ = 5603692416.

The previous prime is 21020020103. The next prime is 21020020121. The reversal of 21020020110 is 1102002012.

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 = 21020020092 and 21020020101.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 290869 + ... + 355871.

It is an arithmetic number, because the mean of its divisors is an integer number (1138918833).

Almost surely, 2^21020020110 is an apocalyptic number.

21020020110 is an abundant number, since it is smaller than the sum of its proper divisors (33648083874).

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

21020020110 is a wasteful number, since it uses less digits than its factorization.

21020020110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68609 (or 68606 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21020020110 its reverse (1102002012), we get a palindrome (22122022122).

The spelling of 21020020110 in words is "twenty-one billion, twenty million, twenty thousand, one hundred ten".