20145161 has 4 divisors (see below), whose sum is σ = 20155152. Its totient is φ = 20135172.

The previous prime is 20145127. The next prime is 20145163. The reversal of 20145161 is 16154102.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20145161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20145163) 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, 791 + ... + 6396.

It is an arithmetic number, because the mean of its divisors is an integer number (5038788).

Almost surely, 2^20145161 is an apocalyptic number.

It is an amenable number.

20145161 is a deficient number, since it is larger than the sum of its proper divisors (9991).

20145161 is an equidigital number, since it uses as much as digits as its factorization.

20145161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9990.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 20145161 is about 4488.3361059529. The cubic root of 20145161 is about 272.0968918435.

Adding to 20145161 its reverse (16154102), we get a palindrome (36299263).

The spelling of 20145161 in words is "twenty million, one hundred forty-five thousand, one hundred sixty-one".