66186657787 has 16 divisors (see below), whose sum is σ = 72819800064. Its totient is φ = 59884560000.

The previous prime is 66186657763. The next prime is 66186657791. The reversal of 66186657787 is 78775668166.

It is a de Polignac number, because none of the positive numbers 2^k-66186657787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66186757787) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 336289 + ... + 495442.

It is an arithmetic number, because the mean of its divisors is an integer number (4551237504).

Almost surely, 2^66186657787 is an apocalyptic number.

66186657787 is a deficient number, since it is larger than the sum of its proper divisors (6633142277).

66186657787 is a wasteful number, since it uses less digits than its factorization.

66186657787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831930.

The product of its digits is 142248960, while the sum is 67.

The spelling of 66186657787 in words is "sixty-six billion, one hundred eighty-six million, six hundred fifty-seven thousand, seven hundred eighty-seven".