21792173 has 4 divisors (see below), whose sum is σ = 23468508. Its totient is φ = 20115840.

The previous prime is 21792151. The next prime is 21792191. The reversal of 21792173 is 37129712.

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 879844 + 20912329 = 938^2 + 4573^2 .

It is a cyclic number.

It is not a de Polignac number, because 21792173 - 2¹⁰ = 21791149 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 (21792103) 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, 838148 + ... + 838173.

It is an arithmetic number, because the mean of its divisors is an integer number (5867127).

Almost surely, 2^21792173 is an apocalyptic number.

It is an amenable number.

21792173 is a deficient number, since it is larger than the sum of its proper divisors (1676335).

21792173 is a wasteful number, since it uses less digits than its factorization.

21792173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1676334.

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

The square root of 21792173 is about 4668.2087571144. The cubic root of 21792173 is about 279.3188075538.

The spelling of 21792173 in words is "twenty-one million, seven hundred ninety-two thousand, one hundred seventy-three".