243640427 has 2 divisors, whose sum is σ = 243640428. Its totient is φ = 243640426.

The previous prime is 243640399. The next prime is 243640457. The reversal of 243640427 is 724046342.

243640427 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243640427 - 2¹² = 243636331 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 243640393 and 243640402.

It is not a weakly prime, because it can be changed into another prime (243640457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121820213 + 121820214.

It is an arithmetic number, because the mean of its divisors is an integer number (121820214).

Almost surely, 2^243640427 is an apocalyptic number.

243640427 is a deficient number, since it is larger than the sum of its proper divisors (1).

243640427 is an equidigital number, since it uses as much as digits as its factorization.

243640427 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32256, while the sum is 32.

The square root of 243640427 is about 15608.9854571013. The cubic root of 243640427 is about 624.5728725392.

Adding to 243640427 its reverse (724046342), we get a palindrome (967686769).

The spelling of 243640427 in words is "two hundred forty-three million, six hundred forty thousand, four hundred twenty-seven".