21000210111 has 6 divisors (see below), whose sum is σ = 30333636840. Its totient is φ = 14000140068.

The previous prime is 21000210059. The next prime is 21000210157. The reversal of 21000210111 is 11101200012.

It is a happy number.

It is not a de Polignac number, because 21000210111 - 2⁷ = 21000209983 is a prime.

It is a super-2 number, since 2×21000210111² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 2333356679 = 21000210111 / (2 + 1 + 0 + 0 + 0 + 2 + 1 + 0 + 1 + 1 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 21000210093 and 21000210102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000218111) 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, 1166678331 + ... + 1166678348.

It is an arithmetic number, because the mean of its divisors is an integer number (5055606140).

Almost surely, 2^21000210111 is an apocalyptic number.

21000210111 is a deficient number, since it is larger than the sum of its proper divisors (9333426729).

21000210111 is a wasteful number, since it uses less digits than its factorization.

21000210111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2333356685 (or 2333356682 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21000210111 its reverse (11101200012), we get a palindrome (32101410123).

The spelling of 21000210111 in words is "twenty-one billion, two hundred ten thousand, one hundred eleven".