20145243 has 4 divisors (see below), whose sum is σ = 26860328. Its totient is φ = 13430160.

The previous prime is 20145241. The next prime is 20145269. The reversal of 20145243 is 34254102.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20145243 - 2¹ = 20145241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20145241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3357538 + ... + 3357543.

It is an arithmetic number, because the mean of its divisors is an integer number (6715082).

Almost surely, 2^20145243 is an apocalyptic number.

20145243 is a deficient number, since it is larger than the sum of its proper divisors (6715085).

20145243 is an equidigital number, since it uses as much as digits as its factorization.

20145243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6715084.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20145243 is about 4488.3452407318. The cubic root of 20145243 is about 272.0972610292.

Adding to 20145243 its reverse (34254102), we get a palindrome (54399345).

The spelling of 20145243 in words is "twenty million, one hundred forty-five thousand, two hundred forty-three".