243216437 has 2 divisors, whose sum is σ = 243216438. Its totient is φ = 243216436.

The previous prime is 243216419. The next prime is 243216451. The reversal of 243216437 is 734612342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 173343556 + 69872881 = 13166^2 + 8359^2 .

It is a cyclic number.

It is not a de Polignac number, because 243216437 - 2¹² = 243212341 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243216487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121608218 + 121608219.

It is an arithmetic number, because the mean of its divisors is an integer number (121608219).

Almost surely, 2^243216437 is an apocalyptic number.

It is an amenable number.

243216437 is a deficient number, since it is larger than the sum of its proper divisors (1).

243216437 is an equidigital number, since it uses as much as digits as its factorization.

243216437 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 32.

The square root of 243216437 is about 15595.3979429831. The cubic root of 243216437 is about 624.2103623493.

Adding to 243216437 its reverse (734612342), we get a palindrome (977828779).

The spelling of 243216437 in words is "two hundred forty-three million, two hundred sixteen thousand, four hundred thirty-seven".