666781137960 has 256 divisors, whose sum is σ = 2426120294400. Its totient is φ = 143113900032.

The previous prime is 666781137959. The next prime is 666781137973. The reversal of 666781137960 is 69731187666.

It is a hoax number, since the sum of its digits (60) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a junction number, because it is equal to n+sod(n) for n = 666781137894 and 666781137903.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6215739 + ... + 6322101.

It is an arithmetic number, because the mean of its divisors is an integer number (9477032400).

Almost surely, 2^666781137960 is an apocalyptic number.

666781137960 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 666781137960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1213060147200).

666781137960 is an abundant number, since it is smaller than the sum of its proper divisors (1759339156440).

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

666781137960 is a wasteful number, since it uses less digits than its factorization.

666781137960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106840 (or 106836 counting only the distinct ones).

The product of its (nonzero) digits is 13716864, while the sum is 60.

The spelling of 666781137960 in words is "six hundred sixty-six billion, seven hundred eighty-one million, one hundred thirty-seven thousand, nine hundred sixty".