21000012111111 has 32 divisors (see below), whose sum is σ = 32333619352320. Its totient is φ = 12002631379200.

The previous prime is 21000012111083. The next prime is 21000012111121. The reversal of 21000012111111 is 11111121000012.

It is not a de Polignac number, because 21000012111111 - 2⁷ = 21000012110983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000012111121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 255116830 + ... + 255199131.

It is an arithmetic number, because the mean of its divisors is an integer number (1010425604760).

Almost surely, 2^{21000012111111} is an apocalyptic number.

21000012111111 is a deficient number, since it is larger than the sum of its proper divisors (11333607241209).

21000012111111 is a wasteful number, since it uses less digits than its factorization.

21000012111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510316047.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 21000012111111 its reverse (11111121000012), we get a palindrome (32111133111123).

It can be divided in two parts, 21000012 and 111111, that multiplied together give a palindrome (2333332333332).

The spelling of 21000012111111 in words is "twenty-one trillion, twelve million, one hundred eleven thousand, one hundred eleven".