243721103 has 2 divisors, whose sum is σ = 243721104. Its totient is φ = 243721102.

The previous prime is 243721099. The next prime is 243721123. The reversal of 243721103 is 301127342.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243721103 - 2² = 243721099 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243721123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121860551 + 121860552.

It is an arithmetic number, because the mean of its divisors is an integer number (121860552).

Almost surely, 2^243721103 is an apocalyptic number.

243721103 is a deficient number, since it is larger than the sum of its proper divisors (1).

243721103 is an equidigital number, since it uses as much as digits as its factorization.

243721103 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 243721103 is about 15611.5695239140. The cubic root of 243721103 is about 624.6418026440.

Adding to 243721103 its reverse (301127342), we get a palindrome (544848445).

The spelling of 243721103 in words is "two hundred forty-three million, seven hundred twenty-one thousand, one hundred three".