66005508987 has 24 divisors (see below), whose sum is σ = 107860858560. Its totient is φ = 40003337160.

The previous prime is 66005508979. The next prime is 66005509007. The reversal of 66005508987 is 78980550066.

66005508987 is a `hidden beast` number, since 6 + 6 + 0 + 0 + 550 + 8 + 9 + 87 = 666.

It is not a de Polignac number, because 66005508987 - 2³ = 66005508979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66005508917) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12344037 + ... + 12349382.

It is an arithmetic number, because the mean of its divisors is an integer number (4494202440).

Almost surely, 2^66005508987 is an apocalyptic number.

66005508987 is a deficient number, since it is larger than the sum of its proper divisors (41855349573).

66005508987 is a wasteful number, since it uses less digits than its factorization.

66005508987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24693445 (or 24693433 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 66005508987 in words is "sixty-six billion, five million, five hundred eight thousand, nine hundred eighty-seven".