666558900 has 216 divisors, whose sum is σ = 2465508864. Its totient is φ = 147398400.

The previous prime is 666558887. The next prime is 666558911. The reversal of 666558900 is 9855666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 193594 + ... + 197006.

Almost surely, 2^666558900 is an apocalyptic number.

666558900 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666558900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1232754432).

666558900 is an abundant number, since it is smaller than the sum of its proper divisors (1798949964).

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

666558900 is a wasteful number, since it uses less digits than its factorization.

666558900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3471 (or 3461 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The square root of 666558900 is about 25817.8019978464. The cubic root of 666558900 is about 873.5333907723.

The spelling of 666558900 in words is "six hundred sixty-six million, five hundred fifty-eight thousand, nine hundred".