21232231213221 has 32 divisors (see below), whose sum is σ = 35948999761920. Its totient is φ = 12132619681392.

The previous prime is 21232231213189. The next prime is 21232231213243. The reversal of 21232231213221 is 12231213223212.

21232231213221 is a `hidden beast` number, since 2 + 1 + 2 + 3 + 22 + 312 + 1 + 322 + 1 = 666.

It is not a de Polignac number, because 21232231213221 - 2⁵ = 21232231213189 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232231212221) 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, 36045556 + ... + 36629858.

It is an arithmetic number, because the mean of its divisors is an integer number (1123406242560).

Almost surely, 2^{21232231213221} is an apocalyptic number.

21232231213221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21232231213221 is a deficient number, since it is larger than the sum of its proper divisors (14716768548699).

21232231213221 is a wasteful number, since it uses less digits than its factorization.

21232231213221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776582 (or 776576 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

Adding to 21232231213221 its reverse (12231213223212), we get a palindrome (33463444436433).

The spelling of 21232231213221 in words is "twenty-one trillion, two hundred thirty-two billion, two hundred thirty-one million, two hundred thirteen thousand, two hundred twenty-one".