172745561 has 4 divisors (see below), whose sum is σ = 173710800. Its totient is φ = 171780324.

The previous prime is 172745519. The next prime is 172745581. The reversal of 172745561 is 165547271.

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 172745561 - 2¹⁴ = 172729177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172745581) 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, 482351 + ... + 482708.

It is an arithmetic number, because the mean of its divisors is an integer number (43427700).

Almost surely, 2^172745561 is an apocalyptic number.

It is an amenable number.

172745561 is a deficient number, since it is larger than the sum of its proper divisors (965239).

172745561 is an equidigital number, since it uses as much as digits as its factorization.

172745561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 965238.

The product of its digits is 58800, while the sum is 38.

The square root of 172745561 is about 13143.2705594917. The cubic root of 172745561 is about 556.9321623497.

The spelling of 172745561 in words is "one hundred seventy-two million, seven hundred forty-five thousand, five hundred sixty-one".