21224331606161 has 8 divisors (see below), whose sum is σ = 21227698575720. Its totient is φ = 21220964923392.

The previous prime is 21224331606103. The next prime is 21224331606193. The reversal of 21224331606161 is 16160613342212.

It can be written as a sum of positive squares in 4 ways, for example, as 570206214400 + 20654125391761 = 755120^2 + 4544681^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21224331606161 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21224331606061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 183016151 + ... + 183132083.

It is an arithmetic number, because the mean of its divisors is an integer number (2653462321965).

Almost surely, 2^{21224331606161} is an apocalyptic number.

It is an amenable number.

21224331606161 is a deficient number, since it is larger than the sum of its proper divisors (3366969559).

21224331606161 is a wasteful number, since it uses less digits than its factorization.

21224331606161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143395.

The product of its (nonzero) digits is 62208, while the sum is 38.

Adding to 21224331606161 its reverse (16160613342212), we get a palindrome (37384944948373).

The spelling of 21224331606161 in words is "twenty-one trillion, two hundred twenty-four billion, three hundred thirty-one million, six hundred six thousand, one hundred sixty-one".