2687666661638 has 16 divisors (see below), whose sum is σ = 4636775245344. Its totient is φ = 1144520470080.

The previous prime is 2687666661607. The next prime is 2687666661643. The reversal of 2687666661638 is 8361666667862.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 611386943 + ... + 611391338.

It is an arithmetic number, because the mean of its divisors is an integer number (289798452834).

Almost surely, 2^{2687666661638} is an apocalyptic number.

2687666661638 is a deficient number, since it is larger than the sum of its proper divisors (1949108583706).

2687666661638 is a wasteful number, since it uses less digits than its factorization.

2687666661638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222778447.

The product of its digits is 752467968, while the sum is 71.

The spelling of 2687666661638 in words is "two trillion, six hundred eighty-seven billion, six hundred sixty-six million, six hundred sixty-one thousand, six hundred thirty-eight".