21000211111111 has 4 divisors (see below), whose sum is σ = 21313647097912. Its totient is φ = 20686775124312.

The previous prime is 21000211111109. The next prime is 21000211111129. The reversal of 21000211111111 is 11111111200012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21000211111111 - 2¹ = 21000211111109 is a prime.

It is a super-2 number, since 2×21000211111111² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

21000211111111 is a modest number, since divided by 11111111 gives 210002 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 21000211111091 and 21000211111100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000211111151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156717993300 + ... + 156717993433.

It is an arithmetic number, because the mean of its divisors is an integer number (5328411774478).

Almost surely, 2^{21000211111111} is an apocalyptic number.

21000211111111 is a deficient number, since it is larger than the sum of its proper divisors (313435986801).

21000211111111 is an equidigital number, since it uses as much as digits as its factorization.

21000211111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313435986800.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 21000211111111 its reverse (11111111200012), we get a palindrome (32111322311123).

The spelling of 21000211111111 in words is "twenty-one trillion, two hundred eleven million, one hundred eleven thousand, one hundred eleven".