20530243 has 4 divisors (see below), whose sum is σ = 20545488. Its totient is φ = 20515000.

The previous prime is 20530229. The next prime is 20530247. The reversal of 20530243 is 34203502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34203502 = 2 ⋅17101751.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20530243 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20530243.

It is not an unprimeable number, because it can be changed into a prime (20530247) 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, 5383 + ... + 8368.

It is an arithmetic number, because the mean of its divisors is an integer number (5136372).

Almost surely, 2^20530243 is an apocalyptic number.

20530243 is a deficient number, since it is larger than the sum of its proper divisors (15245).

20530243 is a wasteful number, since it uses less digits than its factorization.

20530243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15244.

The product of its (nonzero) digits is 720, while the sum is 19.

The square root of 20530243 is about 4531.0311188514. The cubic root of 20530243 is about 273.8197039684.

Adding to 20530243 its reverse (34203502), we get a palindrome (54733745).

The spelling of 20530243 in words is "twenty million, five hundred thirty thousand, two hundred forty-three".