21102012011111 has 6 divisors (see below), whose sum is σ = 22416324178200. Its totient is φ = 19860717186656.

The previous prime is 21102012011053. The next prime is 21102012011123. The reversal of 21102012011111 is 11111021020112.

It is not a de Polignac number, because 21102012011111 - 2⁴² = 16703965500007 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102012011191) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36508671011 + ... + 36508671588.

It is an arithmetic number, because the mean of its divisors is an integer number (3736054029700).

Almost surely, 2^{21102012011111} is an apocalyptic number.

21102012011111 is a deficient number, since it is larger than the sum of its proper divisors (1314312167089).

21102012011111 is an equidigital number, since it uses as much as digits as its factorization.

21102012011111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73017342633 (or 73017342616 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21102012011111 its reverse (11111021020112), we get a palindrome (32213033031223).

Subtracting from 21102012011111 its reverse (11111021020112), we obtain a palindrome (9990990990999).

The spelling of 21102012011111 in words is "twenty-one trillion, one hundred two billion, twelve million, eleven thousand, one hundred eleven".