21134173 has 2 divisors, whose sum is σ = 21134174. Its totient is φ = 21134172.

The previous prime is 21134143. The next prime is 21134221. The reversal of 21134173 is 37143112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21132409 + 1764 = 4597^2 + 42^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21134173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21134123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10567086 + 10567087.

It is an arithmetic number, because the mean of its divisors is an integer number (10567087).

Almost surely, 2^21134173 is an apocalyptic number.

It is an amenable number.

21134173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21134173 is an equidigital number, since it uses as much as digits as its factorization.

21134173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 504, while the sum is 22.

The square root of 21134173 is about 4597.1918602556. The cubic root of 21134173 is about 276.4787470843.

Adding to 21134173 its reverse (37143112), we get a palindrome (58277285).

It can be divided in two parts, 211 and 34173, that multiplied together give a triangular number (7210503 = T₃₇₉₇).

The spelling of 21134173 in words is "twenty-one million, one hundred thirty-four thousand, one hundred seventy-three".