66644475558 has 8 divisors (see below), whose sum is σ = 133288951128. Its totient is φ = 22214825184.

The previous prime is 66644475551. The next prime is 66644475571. The reversal of 66644475558 is 85557444666.

It is a sphenic number, since it is the product of 3 distinct primes.

66644475558 is an admirable number.

It is a super-3 number, since 3×66644475558³ (a number of 33 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66644475551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5553706291 + ... + 5553706302.

It is an arithmetic number, because the mean of its divisors is an integer number (16661118891).

Almost surely, 2^66644475558 is an apocalyptic number.

66644475558 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

66644475558 is a wasteful number, since it uses less digits than its factorization.

66644475558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11107412598.

The product of its digits is 96768000, while the sum is 60.

The spelling of 66644475558 in words is "sixty-six billion, six hundred forty-four million, four hundred seventy-five thousand, five hundred fifty-eight".