20540189 has 4 divisors (see below), whose sum is σ = 20625660. Its totient is φ = 20454720.

The previous prime is 20540171. The next prime is 20540209. The reversal of 20540189 is 98104502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98104502 = 2 ⋅49052251.

It can be written as a sum of positive squares in 2 ways, for example, as 13935289 + 6604900 = 3733^2 + 2570^2 .

It is a cyclic number.

It is not a de Polignac number, because 20540189 - 2⁸ = 20539933 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20540129) 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, 42374 + ... + 42855.

It is an arithmetic number, because the mean of its divisors is an integer number (5156415).

Almost surely, 2^20540189 is an apocalyptic number.

It is an amenable number.

20540189 is a deficient number, since it is larger than the sum of its proper divisors (85471).

20540189 is an equidigital number, since it uses as much as digits as its factorization.

20540189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85470.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 20540189 is about 4532.1285286276. The cubic root of 20540189 is about 273.8639146986.

The spelling of 20540189 in words is "twenty million, five hundred forty thousand, one hundred eighty-nine".