161020321 has 16 divisors (see below), whose sum is σ = 204854400. Its totient is φ = 125467440.

The previous prime is 161020283. The next prime is 161020331. The reversal of 161020321 is 123020161.

161020321 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 161020321 - 2¹³ = 161012129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161020295 and 161020304.

It is not an unprimeable number, because it can be changed into a prime (161020331) 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, 17566 + ... + 25111.

It is an arithmetic number, because the mean of its divisors is an integer number (12803400).

Almost surely, 2^161020321 is an apocalyptic number.

161020321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161020321 is a deficient number, since it is larger than the sum of its proper divisors (43834079).

161020321 is an equidigital number, since it uses as much as digits as its factorization.

161020321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42709 (or 42695 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 161020321 is about 12689.3782747619. The cubic root of 161020321 is about 544.0350695114.

Adding to 161020321 its reverse (123020161), we get a palindrome (284040482).

The spelling of 161020321 in words is "one hundred sixty-one million, twenty thousand, three hundred twenty-one".