666984739680 has 576 divisors, whose sum is σ = 2689767295488. Its totient is φ = 147335454720.

The previous prime is 666984739651. The next prime is 666984739703. The reversal of 666984739680 is 86937489666.

666984739680 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 666984739599 and 666984739608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 44213419 + ... + 44228501.

It is an arithmetic number, because the mean of its divisors is an integer number (4669734888).

Almost surely, 2^666984739680 is an apocalyptic number.

666984739680 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 666984739680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1344883647744).

666984739680 is an abundant number, since it is smaller than the sum of its proper divisors (2022782555808).

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

666984739680 is a wasteful number, since it uses less digits than its factorization.

666984739680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15259 (or 15248 counting only the distinct ones).

The product of its (nonzero) digits is 564350976, while the sum is 72.

The spelling of 666984739680 in words is "six hundred sixty-six billion, nine hundred eighty-four million, seven hundred thirty-nine thousand, six hundred eighty".