21100012111 has 16 divisors (see below), whose sum is σ = 22580244288. Its totient is φ = 19646656000.

The previous prime is 21100012103. The next prime is 21100012147. The reversal of 21100012111 is 11121000112.

It is a cyclic number.

It is not a de Polignac number, because 21100012111 - 2³ = 21100012103 is a prime.

It is a super-2 number, since 2×21100012111² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100012181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2559366 + ... + 2567596.

It is an arithmetic number, because the mean of its divisors is an integer number (1411265268).

Almost surely, 2^21100012111 is an apocalyptic number.

21100012111 is a deficient number, since it is larger than the sum of its proper divisors (1480232177).

21100012111 is a wasteful number, since it uses less digits than its factorization.

21100012111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9842.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21100012111 its reverse (11121000112), we get a palindrome (32221012223).

It can be divided in two parts, 2110001 and 2111, that added together give a palindrome (2112112).

The spelling of 21100012111 in words is "twenty-one billion, one hundred million, twelve thousand, one hundred eleven".