21020110120 has 16 divisors (see below), whose sum is σ = 47295247860. Its totient is φ = 8408044032.

The previous prime is 21020110091. The next prime is 21020110121. The reversal of 21020110120 is 2101102012.

It can be written as a sum of positive squares in 2 ways, for example, as 17791824996 + 3228285124 = 133386^2 + 56818^2 .

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 = 21020110097 and 21020110106.

It is not an unprimeable number, because it can be changed into a prime (21020110121) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 262751337 + ... + 262751416.

Almost surely, 2^21020110120 is an apocalyptic number.

21020110120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020110120 is an abundant number, since it is smaller than the sum of its proper divisors (26275137740).

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

21020110120 is a wasteful number, since it uses less digits than its factorization.

21020110120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525502764 (or 525502760 counting only the distinct ones).

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

Adding to 21020110120 its reverse (2101102012), we get a palindrome (23121212132).

The spelling of 21020110120 in words is "twenty-one billion, twenty million, one hundred ten thousand, one hundred twenty".