21761130173 has 4 divisors (see below), whose sum is σ = 21799375260. Its totient is φ = 21722885088.

The previous prime is 21761130151. The next prime is 21761130221. The reversal of 21761130173 is 37103116712.

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 4653013369 + 17108116804 = 68213^2 + 130798^2 .

It is a cyclic number.

It is not a de Polignac number, because 21761130173 - 2³⁴ = 4581260989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21761130473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19121690 + ... + 19122827.

It is an arithmetic number, because the mean of its divisors is an integer number (5449843815).

Almost surely, 2^21761130173 is an apocalyptic number.

It is an amenable number.

21761130173 is a deficient number, since it is larger than the sum of its proper divisors (38245087).

21761130173 is an equidigital number, since it uses as much as digits as its factorization.

21761130173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38245086.

The product of its (nonzero) digits is 5292, while the sum is 32.

Adding to 21761130173 its reverse (37103116712), we get a palindrome (58864246885).

The spelling of 21761130173 in words is "twenty-one billion, seven hundred sixty-one million, one hundred thirty thousand, one hundred seventy-three".