161728573 has 4 divisors (see below), whose sum is σ = 163329948. Its totient is φ = 160127200.

The previous prime is 161728549. The next prime is 161728613. The reversal of 161728573 is 375827161.

161728573 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 68856804 + 92871769 = 8298^2 + 9637^2 .

It is a cyclic number.

It is not a de Polignac number, because 161728573 - 2²⁵ = 128174141 is a prime.

It is a super-2 number, since 2×161728573² = 52312262649232658, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161728543) 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, 800536 + ... + 800737.

It is an arithmetic number, because the mean of its divisors is an integer number (40832487).

Almost surely, 2^161728573 is an apocalyptic number.

It is an amenable number.

161728573 is a deficient number, since it is larger than the sum of its proper divisors (1601375).

161728573 is a wasteful number, since it uses less digits than its factorization.

161728573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1601374.

The product of its digits is 70560, while the sum is 40.

The square root of 161728573 is about 12717.2549317846. The cubic root of 161728573 is about 544.8315535875.

The spelling of 161728573 in words is "one hundred sixty-one million, seven hundred twenty-eight thousand, five hundred seventy-three".