638611600243 has 2 divisors, whose sum is σ = 638611600244. Its totient is φ = 638611600242.

The previous prime is 638611600241. The next prime is 638611600309. The reversal of 638611600243 is 342006116836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638611600243 - 2¹ = 638611600241 is a prime.

Together with 638611600241, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 638611600196 and 638611600205.

It is not a weakly prime, because it can be changed into another prime (638611600241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319305800121 + 319305800122.

It is an arithmetic number, because the mean of its divisors is an integer number (319305800122).

Almost surely, 2^638611600243 is an apocalyptic number.

638611600243 is a deficient number, since it is larger than the sum of its proper divisors (1).

638611600243 is an equidigital number, since it uses as much as digits as its factorization.

638611600243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 40.

The spelling of 638611600243 in words is "six hundred thirty-eight billion, six hundred eleven million, six hundred thousand, two hundred forty-three".