20516443 has 4 divisors (see below), whose sum is σ = 20631240. Its totient is φ = 20401648.

The previous prime is 20516423. The next prime is 20516471. The reversal of 20516443 is 34461502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34461502 = 2 ⋅17230751.

It is a cyclic number.

It is not a de Polignac number, because 20516443 - 2¹³ = 20508251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20516423) 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, 57130 + ... + 57487.

It is an arithmetic number, because the mean of its divisors is an integer number (5157810).

Almost surely, 2^20516443 is an apocalyptic number.

20516443 is a deficient number, since it is larger than the sum of its proper divisors (114797).

20516443 is a wasteful number, since it uses less digits than its factorization.

20516443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114796.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 20516443 is about 4529.5080306806. The cubic root of 20516443 is about 273.7583382572.

Adding to 20516443 its reverse (34461502), we get a palindrome (54977945).

The spelling of 20516443 in words is "twenty million, five hundred sixteen thousand, four hundred forty-three".