21111020200111 has 16 divisors (see below), whose sum is σ = 21505610476800. Its totient is φ = 20718909731520.

The previous prime is 21111020200097. The next prime is 21111020200147. The reversal of 21111020200111 is 11100202011112.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21111020200111 - 2¹¹ = 21111020198063 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111020200091 and 21111020200100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111020200181) 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, 19169635 + ... + 20240971.

It is an arithmetic number, because the mean of its divisors is an integer number (1344100654800).

Almost surely, 2^{21111020200111} is an apocalyptic number.

21111020200111 is a deficient number, since it is larger than the sum of its proper divisors (394590276689).

21111020200111 is a wasteful number, since it uses less digits than its factorization.

21111020200111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072494.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21111020200111 its reverse (11100202011112), we get a palindrome (32211222211223).

The spelling of 21111020200111 in words is "twenty-one trillion, one hundred eleven billion, twenty million, two hundred thousand, one hundred eleven".