21704033161 has 4 divisors (see below), whose sum is σ = 22980741012. Its totient is φ = 20427325312.

The previous prime is 21704033137. The next prime is 21704033177. The reversal of 21704033161 is 16133040712.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16430368761 + 5273664400 = 128181^2 + 72620^2 .

It is a cyclic number.

It is not a de Polignac number, because 21704033161 - 2¹⁹ = 21703508873 is a prime.

It is a super-3 number, since 3×21704033161³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21704033111) 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, 638353900 + ... + 638353933.

It is an arithmetic number, because the mean of its divisors is an integer number (5745185253).

Almost surely, 2^21704033161 is an apocalyptic number.

It is an amenable number.

21704033161 is a deficient number, since it is larger than the sum of its proper divisors (1276707851).

21704033161 is a wasteful number, since it uses less digits than its factorization.

21704033161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1276707850.

The product of its (nonzero) digits is 3024, while the sum is 28.

Adding to 21704033161 its reverse (16133040712), we get a palindrome (37837073873).

The spelling of 21704033161 in words is "twenty-one billion, seven hundred four million, thirty-three thousand, one hundred sixty-one".