21230212111 has 4 divisors (see below), whose sum is σ = 21232465072. Its totient is φ = 21227959152.

The previous prime is 21230212103. The next prime is 21230212139. The reversal of 21230212111 is 11121203212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21230212111 - 2³ = 21230212103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230212811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1112286 + ... + 1131211.

It is an arithmetic number, because the mean of its divisors is an integer number (5308116268).

Almost surely, 2^21230212111 is an apocalyptic number.

21230212111 is a deficient number, since it is larger than the sum of its proper divisors (2252961).

21230212111 is an equidigital number, since it uses as much as digits as its factorization.

21230212111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2252960.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21230212111 its reverse (11121203212), we get a palindrome (32351415323).

The spelling of 21230212111 in words is "twenty-one billion, two hundred thirty million, two hundred twelve thousand, one hundred eleven".