21734173 has 2 divisors, whose sum is σ = 21734174. Its totient is φ = 21734172.

The previous prime is 21734171. The next prime is 21734189. The reversal of 21734173 is 37143712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18207289 + 3526884 = 4267^2 + 1878^2 .

It is a cyclic number.

It is not a de Polignac number, because 21734173 - 2¹ = 21734171 is a prime.

Together with 21734171, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21734171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10867086 + 10867087.

It is an arithmetic number, because the mean of its divisors is an integer number (10867087).

Almost surely, 2^21734173 is an apocalyptic number.

It is an amenable number.

21734173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21734173 is an equidigital number, since it uses as much as digits as its factorization.

21734173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3528, while the sum is 28.

The square root of 21734173 is about 4661.9923852362. The cubic root of 21734173 is about 279.0707844876.

Adding to 21734173 its reverse (37143712), we get a palindrome (58877885).

The spelling of 21734173 in words is "twenty-one million, seven hundred thirty-four thousand, one hundred seventy-three".