20660243 has 2 divisors, whose sum is σ = 20660244. Its totient is φ = 20660242.

The previous prime is 20660231. The next prime is 20660251. The reversal of 20660243 is 34206602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20660243 - 2¹⁸ = 20398099 is a prime.

It is not a weakly prime, because it can be changed into another prime (20660203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10330121 + 10330122.

It is an arithmetic number, because the mean of its divisors is an integer number (10330122).

Almost surely, 2^20660243 is an apocalyptic number.

20660243 is a deficient number, since it is larger than the sum of its proper divisors (1).

20660243 is an equidigital number, since it uses as much as digits as its factorization.

20660243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 20660243 is about 4545.3540016153. The cubic root of 20660243 is about 274.3964415938.

Adding to 20660243 its reverse (34206602), we get a palindrome (54866845).

The spelling of 20660243 in words is "twenty million, six hundred sixty thousand, two hundred forty-three".