638468000549 has 2 divisors, whose sum is σ = 638468000550. Its totient is φ = 638468000548.

The previous prime is 638468000531. The next prime is 638468000593. The reversal of 638468000549 is 945000864836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 473319232324 + 165148768225 = 687982^2 + 406385^2 .

It is a cyclic number.

It is not a de Polignac number, because 638468000549 - 2⁸ = 638468000293 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 638468000549.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638468000749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319234000274 + 319234000275.

It is an arithmetic number, because the mean of its divisors is an integer number (319234000275).

Almost surely, 2^638468000549 is an apocalyptic number.

It is an amenable number.

638468000549 is a deficient number, since it is larger than the sum of its proper divisors (1).

638468000549 is an equidigital number, since it uses as much as digits as its factorization.

638468000549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4976640, while the sum is 53.

The spelling of 638468000549 in words is "six hundred thirty-eight billion, four hundred sixty-eight million, five hundred forty-nine", and thus it is an aban number.