161573252305 has 4 divisors (see below), whose sum is σ = 193887902772. Its totient is φ = 129258601840.

The previous prime is 161573252287. The next prime is 161573252341. The reversal of 161573252305 is 503252375161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 503252375161 = 177131 ⋅2841131.

It can be written as a sum of positive squares in 2 ways, for example, as 21524410944 + 140048841361 = 146712^2 + 374231^2 .

It is not a de Polignac number, because 161573252305 - 2¹³ = 161573244113 is a prime.

It is a super-2 number, since 2×161573252305² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16157325226 + ... + 16157325235.

It is an arithmetic number, because the mean of its divisors is an integer number (48471975693).

Almost surely, 2^161573252305 is an apocalyptic number.

It is an amenable number.

161573252305 is a deficient number, since it is larger than the sum of its proper divisors (32314650467).

161573252305 is an equidigital number, since it uses as much as digits as its factorization.

161573252305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32314650466.

The product of its (nonzero) digits is 189000, while the sum is 40.

The spelling of 161573252305 in words is "one hundred sixty-one billion, five hundred seventy-three million, two hundred fifty-two thousand, three hundred five".