666420000 has 240 divisors, whose sum is σ = 2267274240. Its totient is φ = 171136000.

The previous prime is 666419981. The next prime is 666420011. The reversal of 666420000 is 24666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1739809 + ... + 1740191.

It is an arithmetic number, because the mean of its divisors is an integer number (9446976).

Almost surely, 2^666420000 is an apocalyptic number.

666420000 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 666420000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1133637120).

666420000 is an abundant number, since it is smaller than the sum of its proper divisors (1600854240).

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

666420000 is a wasteful number, since it uses less digits than its factorization.

666420000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 666420000 is about 25815.1118533312. Note that the first 3 decimals coincide. The cubic root of 666420000 is about 873.4727098548.

Adding to 666420000 its reverse (24666), we get a palindrome (666444666).

The spelling of 666420000 in words is "six hundred sixty-six million, four hundred twenty thousand".