20161345 has 4 divisors (see below), whose sum is σ = 24193620. Its totient is φ = 16129072.

The previous prime is 20161343. The next prime is 20161397. The reversal of 20161345 is 54316102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54316102 = 2 ⋅27158051.

It can be written as a sum of positive squares in 2 ways, for example, as 13571856 + 6589489 = 3684^2 + 2567^2 .

It is a cyclic number.

It is not a de Polignac number, because 20161345 - 2¹ = 20161343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20161343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2016130 + ... + 2016139.

It is an arithmetic number, because the mean of its divisors is an integer number (6048405).

Almost surely, 2^20161345 is an apocalyptic number.

It is an amenable number.

20161345 is a deficient number, since it is larger than the sum of its proper divisors (4032275).

20161345 is an equidigital number, since it uses as much as digits as its factorization.

20161345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4032274.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 20161345 is about 4490.1386392850. The cubic root of 20161345 is about 272.1697370855.

Adding to 20161345 its reverse (54316102), we get a palindrome (74477447).

The spelling of 20161345 in words is "twenty million, one hundred sixty-one thousand, three hundred forty-five".