666266720000 has 540 divisors, whose sum is σ = 2047336830000. Its totient is φ = 214953984000.

The previous prime is 666266719999. The next prime is 666266720027. The reversal of 666266720000 is 27662666.

It is a super-2 number, since 2×666266720000² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 666266720000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 133277501 + ... + 133282499.

It is an arithmetic number, because the mean of its divisors is an integer number (3791364500).

Almost surely, 2^666266720000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666266720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1023668415000).

666266720000 is an abundant number, since it is smaller than the sum of its proper divisors (1381070110000).

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

666266720000 is an equidigital number, since it uses as much as digits as its factorization.

666266720000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5066 (or 5030 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 41.

The spelling of 666266720000 in words is "six hundred sixty-six billion, two hundred sixty-six million, seven hundred twenty thousand".