666214560 has 288 divisors, whose sum is σ = 2506375872. Its totient is φ = 159805440.

The previous prime is 666214543. The next prime is 666214561. The reversal of 666214560 is 65412666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666214561) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 2169927 + ... + 2170233.

It is an arithmetic number, because the mean of its divisors is an integer number (8702694).

Almost surely, 2^666214560 is an apocalyptic number.

666214560 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 666214560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1253187936).

666214560 is an abundant number, since it is smaller than the sum of its proper divisors (1840161312).

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

666214560 is a wasteful number, since it uses less digits than its factorization.

666214560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476 (or 465 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 666214560 is about 25811.1324819350. The cubic root of 666214560 is about 873.3829443034.

The spelling of 666214560 in words is "six hundred sixty-six million, two hundred fourteen thousand, five hundred sixty".