66538520166 has 24 divisors (see below), whose sum is σ = 141365579400. Its totient is φ = 20874829312.

The previous prime is 66538520161. The next prime is 66538520189. The reversal of 66538520166 is 66102583566.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66538520161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19184691 + ... + 19188158.

It is an arithmetic number, because the mean of its divisors is an integer number (5890232475).

Almost surely, 2^66538520166 is an apocalyptic number.

66538520166 is an abundant number, since it is smaller than the sum of its proper divisors (74827059234).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66538520166 is a wasteful number, since it uses less digits than its factorization.

66538520166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38372888 (or 38372871 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 48.

The spelling of 66538520166 in words is "sixty-six billion, five hundred thirty-eight million, five hundred twenty thousand, one hundred sixty-six".