21006113020 has 24 divisors (see below), whose sum is σ = 45188761968. Its totient is φ = 8197507200.

The previous prime is 21006112999. The next prime is 21006113027. The reversal of 21006113020 is 2031160012.

It is a junction number, because it is equal to n+sod(n) for n = 21006112985 and 21006113003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21006113027) 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, 12807786 + ... + 12809425.

It is an arithmetic number, because the mean of its divisors is an integer number (1882865082).

Almost surely, 2^21006113020 is an apocalyptic number.

21006113020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21006113020 is an abundant number, since it is smaller than the sum of its proper divisors (24182648948).

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

21006113020 is a wasteful number, since it uses less digits than its factorization.

21006113020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25617261 (or 25617259 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21006113020 its reverse (2031160012), we get a palindrome (23037273032).

The spelling of 21006113020 in words is "twenty-one billion, six million, one hundred thirteen thousand, twenty".