173345721 has 16 divisors (see below), whose sum is σ = 243609600. Its totient is φ = 109338768.

The previous prime is 173345701. The next prime is 173345737. The reversal of 173345721 is 127543371.

173345721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 173345721 - 2⁶ = 173345657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (173345701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57760 + ... + 60686.

It is an arithmetic number, because the mean of its divisors is an integer number (15225600).

Almost surely, 2^173345721 is an apocalyptic number.

It is an amenable number.

173345721 is a deficient number, since it is larger than the sum of its proper divisors (70263879).

173345721 is a wasteful number, since it uses less digits than its factorization.

173345721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3988.

The product of its digits is 17640, while the sum is 33.

The square root of 173345721 is about 13166.0822190962. The cubic root of 173345721 is about 557.5763893529.

The spelling of 173345721 in words is "one hundred seventy-three million, three hundred forty-five thousand, seven hundred twenty-one".