21222231232221 has 12 divisors (see below), whose sum is σ = 30655469993148. Its totient is φ = 14147629851264.

The previous prime is 21222231232201. The next prime is 21222231232249. The reversal of 21222231232221 is 12223213222212.

21222231232221 is a `hidden beast` number, since 2 + 1 + 2 + 2 + 2 + 2 + 312 + 322 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6986241922500 + 14235989309721 = 2643150^2 + 3773061^2 .

It is not a de Polignac number, because 21222231232221 - 2³¹ = 21220083748573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222231232201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43435530 + ... + 43921403.

It is an arithmetic number, because the mean of its divisors is an integer number (2554622499429).

Almost surely, 2^{21222231232221} is an apocalyptic number.

It is an amenable number.

21222231232221 is a deficient number, since it is larger than the sum of its proper divisors (9433238760927).

21222231232221 is a wasteful number, since it uses less digits than its factorization.

21222231232221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87383932 (or 87383929 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

Adding to 21222231232221 its reverse (12223213222212), we get a palindrome (33445444454433).

The spelling of 21222231232221 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred thirty-one million, two hundred thirty-two thousand, two hundred twenty-one".