21010110111 has 36 divisors (see below), whose sum is σ = 32507648472. Its totient is φ = 13071354912.

The previous prime is 21010110109. The next prime is 21010110113. The reversal of 21010110111 is 11101101012.

It is an interprime number because it is at equal distance from previous prime (21010110109) and next prime (21010110113).

It is not a de Polignac number, because 21010110111 - 2¹ = 21010110109 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21010110093 and 21010110102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010110113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 169425 + ... + 265941.

Almost surely, 2^21010110111 is an apocalyptic number.

21010110111 is a deficient number, since it is larger than the sum of its proper divisors (11497538361).

21010110111 is a wasteful number, since it uses less digits than its factorization.

21010110111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96628 (or 96606 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 9.

Adding to 21010110111 its reverse (11101101012), we get a palindrome (32111211123).

Subtracting from 21010110111 its reverse (11101101012), we obtain a palindrome (9909009099).

The spelling of 21010110111 in words is "twenty-one billion, ten million, one hundred ten thousand, one hundred eleven".