666778596120 has 1536 divisors, whose sum is σ = 2956061952000. Its totient is φ = 132058128384.

The previous prime is 666778596053. The next prime is 666778596131. The reversal of 666778596120 is 21695877666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 1759310091 + ... + 1759310469.

It is an arithmetic number, because the mean of its divisors is an integer number (1924519500).

Almost surely, 2^666778596120 is an apocalyptic number.

666778596120 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 666778596120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1478030976000).

666778596120 is an abundant number, since it is smaller than the sum of its proper divisors (2289283355880).

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

666778596120 is a wasteful number, since it uses less digits than its factorization.

666778596120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461 (or 426 counting only the distinct ones).

The product of its (nonzero) digits is 45722880, while the sum is 63.

The spelling of 666778596120 in words is "six hundred sixty-six billion, seven hundred seventy-eight million, five hundred ninety-six thousand, one hundred twenty".