172724945 has 4 divisors (see below), whose sum is σ = 207269940. Its totient is φ = 138179952.

The previous prime is 172724921. The next prime is 172724971. The reversal of 172724945 is 549427271.

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 121859521 + 50865424 = 11039^2 + 7132^2 .

It is a cyclic number.

It is not a de Polignac number, because 172724945 - 2²⁰ = 171676369 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17272490 + ... + 17272499.

It is an arithmetic number, because the mean of its divisors is an integer number (51817485).

Almost surely, 2^172724945 is an apocalyptic number.

It is an amenable number.

172724945 is a deficient number, since it is larger than the sum of its proper divisors (34544995).

172724945 is an equidigital number, since it uses as much as digits as its factorization.

172724945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34544994.

The product of its digits is 141120, while the sum is 41.

The square root of 172724945 is about 13142.4862564128. The cubic root of 172724945 is about 556.9100061214.

The spelling of 172724945 in words is "one hundred seventy-two million, seven hundred twenty-four thousand, nine hundred forty-five".