21232321211 has 4 divisors (see below), whose sum is σ = 21342333432. Its totient is φ = 21122308992.

The previous prime is 21232321199. The next prime is 21232321273. The reversal of 21232321211 is 11212323212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21232321211 is a prime.

It is a super-2 number, since 2×21232321211² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21232321291) 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, 55005821 + ... + 55006206.

It is an arithmetic number, because the mean of its divisors is an integer number (5335583358).

Almost surely, 2^21232321211 is an apocalyptic number.

21232321211 is a deficient number, since it is larger than the sum of its proper divisors (110012221).

21232321211 is a wasteful number, since it uses less digits than its factorization.

21232321211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110012220.

The product of its digits is 288, while the sum is 20.

Adding to 21232321211 its reverse (11212323212), we get a palindrome (32444644423).

It can be divided in two parts, 212323212 and 11, that multiplied together give a palindrome (2335555332).

The spelling of 21232321211 in words is "twenty-one billion, two hundred thirty-two million, three hundred twenty-one thousand, two hundred eleven".