21002100020111 has 16 divisors (see below), whose sum is σ = 25447451769600. Its totient is φ = 16931643772608.

The previous prime is 21002100020089. The next prime is 21002100020147. The reversal of 21002100020111 is 11102000120012.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21002100020111 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002100020092 and 21002100020101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002100020171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 568004990 + ... + 568041963.

It is an arithmetic number, because the mean of its divisors is an integer number (1590465735600).

Almost surely, 2^{21002100020111} is an apocalyptic number.

21002100020111 is a deficient number, since it is larger than the sum of its proper divisors (4445351749489).

21002100020111 is a wasteful number, since it uses less digits than its factorization.

21002100020111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1136047118.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21002100020111 its reverse (11102000120012), we get a palindrome (32104100140123).

Subtracting from 21002100020111 its reverse (11102000120012), we obtain a palindrome (9900099900099).

The spelling of 21002100020111 in words is "twenty-one trillion, two billion, one hundred million, twenty thousand, one hundred eleven".