638927099947 has 2 divisors, whose sum is σ = 638927099948. Its totient is φ = 638927099946.

The previous prime is 638927099939. The next prime is 638927099983. The reversal of 638927099947 is 749990729836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638927099947 - 2³ = 638927099939 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 638927099947.

It is not a weakly prime, because it can be changed into another prime (638927099147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319463549973 + 319463549974.

It is an arithmetic number, because the mean of its divisors is an integer number (319463549974).

Almost surely, 2^638927099947 is an apocalyptic number.

638927099947 is a deficient number, since it is larger than the sum of its proper divisors (1).

638927099947 is an equidigital number, since it uses as much as digits as its factorization.

638927099947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 370355328, while the sum is 73.

The spelling of 638927099947 in words is "six hundred thirty-eight billion, nine hundred twenty-seven million, ninety-nine thousand, nine hundred forty-seven".