21042041020 has 96 divisors (see below), whose sum is σ = 59329783296. Its totient is φ = 6054048000.

The previous prime is 21042040991. The next prime is 21042041161. The reversal of 21042041020 is 2014024012.

It is a junction number, because it is equal to n+sod(n) for n = 21042040985 and 21042041003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 505506 + ... + 545545.

It is an arithmetic number, because the mean of its divisors is an integer number (618018576).

Almost surely, 2^21042041020 is an apocalyptic number.

21042041020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21042041020 is an abundant number, since it is smaller than the sum of its proper divisors (38287742276).

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

21042041020 is a wasteful number, since it uses less digits than its factorization.

21042041020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051091 (or 1051089 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21042041020 its reverse (2014024012), we get a palindrome (23056065032).

The spelling of 21042041020 in words is "twenty-one billion, forty-two million, forty-one thousand, twenty".