666531000 has 192 divisors, whose sum is σ = 2326521600. Its totient is φ = 171936000.

The previous prime is 666530971. The next prime is 666531011. The reversal of 666531000 is 135666.

It is a super-2 number, since 2×666531000² = 888527147922000000, which contains 22 as substring.

It is a nialpdrome in base 10.

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 47 ways as a sum of consecutive naturals, for example, 277806 + ... + 280194.

It is an arithmetic number, because the mean of its divisors is an integer number (12117300).

Almost surely, 2^666531000 is an apocalyptic number.

666531000 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 666531000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1163260800).

666531000 is an abundant number, since it is smaller than the sum of its proper divisors (1659990600).

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

666531000 is a wasteful number, since it uses less digits than its factorization.

666531000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2447 (or 2430 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 666531000 is about 25817.2616673419. The cubic root of 666531000 is about 873.5212028413.

Adding to 666531000 its reverse (135666), we get a palindrome (666666666).

The spelling of 666531000 in words is "six hundred sixty-six million, five hundred thirty-one thousand".