20542345 has 4 divisors (see below), whose sum is σ = 24650820. Its totient is φ = 16433872.

The previous prime is 20542343. The next prime is 20542349. The reversal of 20542345 is 54324502.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9960336 + 10582009 = 3156^2 + 3253^2 .

It is a cyclic number.

It is not a de Polignac number, because 20542345 - 2¹ = 20542343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20542343) 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, 2054230 + ... + 2054239.

It is an arithmetic number, because the mean of its divisors is an integer number (6162705).

Almost surely, 2^20542345 is an apocalyptic number.

It is an amenable number.

20542345 is a deficient number, since it is larger than the sum of its proper divisors (4108475).

20542345 is an equidigital number, since it uses as much as digits as its factorization.

20542345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4108474.

The product of its (nonzero) digits is 4800, while the sum is 25.

The square root of 20542345 is about 4532.3663797182. The cubic root of 20542345 is about 273.8734964011.

Adding to 20542345 its reverse (54324502), we get a palindrome (74866847).

The spelling of 20542345 in words is "twenty million, five hundred forty-two thousand, three hundred forty-five".