666505551100 has 18 divisors (see below), whose sum is σ = 1446317046104. Its totient is φ = 266602220400.

The previous prime is 666505551071. The next prime is 666505551109. The reversal of 666505551100 is 1155505666.

It is a super-3 number, since 3×666505551100³ (a number of 36 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 (666505551109) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3332527656 + ... + 3332527855.

Almost surely, 2^666505551100 is an apocalyptic number.

It is an amenable number.

666505551100 is an abundant number, since it is smaller than the sum of its proper divisors (779811495004).

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

666505551100 is a wasteful number, since it uses less digits than its factorization.

666505551100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6665055525 (or 6665055518 counting only the distinct ones).

The product of its (nonzero) digits is 135000, while the sum is 40.

The spelling of 666505551100 in words is "six hundred sixty-six billion, five hundred five million, five hundred fifty-one thousand, one hundred".