243540403 has 2 divisors, whose sum is σ = 243540404. Its totient is φ = 243540402.

The previous prime is 243540361. The next prime is 243540439. The reversal of 243540403 is 304045342.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243540403 is a prime.

It is a super-3 number, since 3×243540403³ (a number of 26 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (243540503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121770201 + 121770202.

It is an arithmetic number, because the mean of its divisors is an integer number (121770202).

Almost surely, 2^243540403 is an apocalyptic number.

243540403 is a deficient number, since it is larger than the sum of its proper divisors (1).

243540403 is an equidigital number, since it uses as much as digits as its factorization.

243540403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 25.

The square root of 243540403 is about 15605.7810762550. The cubic root of 243540403 is about 624.4873902449.

Adding to 243540403 its reverse (304045342), we get a palindrome (547585745).

The spelling of 243540403 in words is "two hundred forty-three million, five hundred forty thousand, four hundred three".