66115111555 has 16 divisors (see below), whose sum is σ = 80856486144. Its totient is φ = 51880383360.

The previous prime is 66115111511. The next prime is 66115111567. The reversal of 66115111555 is 55511151166.

It is not a de Polignac number, because 66115111555 - 2⁷ = 66115111427 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1034542 + ... + 1096588.

It is an arithmetic number, because the mean of its divisors is an integer number (5053530384).

Almost surely, 2^66115111555 is an apocalyptic number.

66115111555 is a deficient number, since it is larger than the sum of its proper divisors (14741374589).

66115111555 is a wasteful number, since it uses less digits than its factorization.

66115111555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66126.

The product of its digits is 22500, while the sum is 37.

The spelling of 66115111555 in words is "sixty-six billion, one hundred fifteen million, one hundred eleven thousand, five hundred fifty-five".