66679444497666 has 128 divisors (see below), whose sum is σ = 179177038774272. Its totient is φ = 15976209312000.

The previous prime is 66679444497641. The next prime is 66679444497689.

66679444497666 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×66679444497666² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5061156 + ... + 12608496.

It is an arithmetic number, because the mean of its divisors is an integer number (1399820615424).

Almost surely, 2^{66679444497666} is an apocalyptic number.

66679444497666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 66679444497666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89588519387136).

66679444497666 is an abundant number, since it is smaller than the sum of its proper divisors (112497594276606).

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

66679444497666 is a wasteful number, since it uses less digits than its factorization.

66679444497666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7548848.

The product of its digits is 47405481984, while the sum is 84.

The spelling of 66679444497666 in words is "sixty-six trillion, six hundred seventy-nine billion, four hundred forty-four million, four hundred ninety-seven thousand, six hundred sixty-six".