21102211000021 has 8 divisors (see below), whose sum is σ = 22343790299544. Its totient is φ = 19860662008320.

The previous prime is 21102211000007. The next prime is 21102211000097. The reversal of 21102211000021 is 12000011220112.

It can be written as a sum of positive squares in 4 ways, for example, as 9075457502500 + 12026753497521 = 3012550^2 + 3467961^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21102211000021 - 2⁷ = 21102210999893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102210999965 and 21102211000010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102211000721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6135630 + ... + 8935903.

It is an arithmetic number, because the mean of its divisors is an integer number (2792973787443).

Almost surely, 2^{21102211000021} is an apocalyptic number.

It is an amenable number.

21102211000021 is a deficient number, since it is larger than the sum of its proper divisors (1241579299523).

21102211000021 is a wasteful number, since it uses less digits than its factorization.

21102211000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15153911.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21102211000021 its reverse (12000011220112), we get a palindrome (33102222220133).

The spelling of 21102211000021 in words is "twenty-one trillion, one hundred two billion, two hundred eleven million, twenty-one", and thus it is an aban number.