21030312111 has 32 divisors (see below), whose sum is σ = 30047397120. Its totient is φ = 13037246976.

The previous prime is 21030312071. The next prime is 21030312113. The reversal of 21030312111 is 11121303012.

It is a happy number.

It is not a de Polignac number, because 21030312111 - 2¹⁰ = 21030311087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030312113) 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, 2117820 + ... + 2127726.

It is an arithmetic number, because the mean of its divisors is an integer number (938981160).

Almost surely, 2^21030312111 is an apocalyptic number.

21030312111 is a deficient number, since it is larger than the sum of its proper divisors (9017085009).

21030312111 is a wasteful number, since it uses less digits than its factorization.

21030312111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10423.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21030312111 its reverse (11121303012), we get a palindrome (32151615123).

Subtracting from 21030312111 its reverse (11121303012), we obtain a palindrome (9909009099).

The spelling of 21030312111 in words is "twenty-one billion, thirty million, three hundred twelve thousand, one hundred eleven".