1638541878587 has 2 divisors, whose sum is σ = 1638541878588. Its totient is φ = 1638541878586.

The previous prime is 1638541878551. The next prime is 1638541878679. The reversal of 1638541878587 is 7858781458361.

It is a weak prime.

It is an emirp because it is prime and its reverse (7858781458361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1638541878587 - 2¹⁰ = 1638541877563 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 1638541878587.

It is not a weakly prime, because it can be changed into another prime (1638541878187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819270939293 + 819270939294.

It is an arithmetic number, because the mean of its divisors is an integer number (819270939294).

Almost surely, 2^{1638541878587} is an apocalyptic number.

1638541878587 is a deficient number, since it is larger than the sum of its proper divisors (1).

1638541878587 is an equidigital number, since it uses as much as digits as its factorization.

1638541878587 is an evil number, because the sum of its binary digits is even.

The product of its digits is 361267200, while the sum is 71.

The spelling of 1638541878587 in words is "one trillion, six hundred thirty-eight billion, five hundred forty-one million, eight hundred seventy-eight thousand, five hundred eighty-seven".