21674173 has 2 divisors, whose sum is σ = 21674174. Its totient is φ = 21674172.

The previous prime is 21674171. The next prime is 21674179. The reversal of 21674173 is 37147612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19027044 + 2647129 = 4362^2 + 1627^2 .

It is a cyclic number.

It is not a de Polignac number, because 21674173 - 2¹ = 21674171 is a prime.

Together with 21674171, 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 (21674171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10837086 + 10837087.

It is an arithmetic number, because the mean of its divisors is an integer number (10837087).

Almost surely, 2^21674173 is an apocalyptic number.

It is an amenable number.

21674173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21674173 is an equidigital number, since it uses as much as digits as its factorization.

21674173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 31.

The square root of 21674173 is about 4655.5529209751. The cubic root of 21674173 is about 278.8137441275.

The spelling of 21674173 in words is "twenty-one million, six hundred seventy-four thousand, one hundred seventy-three".