173813921 has 4 divisors (see below), whose sum is σ = 181371072. Its totient is φ = 166256772.

The previous prime is 173813917. The next prime is 173813923. The reversal of 173813921 is 129318371.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 173813921 - 2² = 173813917 is a prime.

It is a super-2 number, since 2×173813921² = 60422558266788482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (173813923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3778541 + ... + 3778586.

It is an arithmetic number, because the mean of its divisors is an integer number (45342768).

Almost surely, 2^173813921 is an apocalyptic number.

It is an amenable number.

173813921 is a deficient number, since it is larger than the sum of its proper divisors (7557151).

173813921 is an equidigital number, since it uses as much as digits as its factorization.

173813921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7557150.

The product of its digits is 9072, while the sum is 35.

The square root of 173813921 is about 13183.8507652355. The cubic root of 173813921 is about 558.0779353980.

The spelling of 173813921 in words is "one hundred seventy-three million, eight hundred thirteen thousand, nine hundred twenty-one".