1666487623680 has 1344 divisors, whose sum is σ = 6759933014016. Its totient is φ = 390168576000.

The previous prime is 1666487623663. The next prime is 1666487623681. The reversal of 1666487623680 is 863267846661.

It is a super-2 number, since 2×1666487623680² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1666487623681) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3394068235 + ... + 3394068725.

It is an arithmetic number, because the mean of its divisors is an integer number (5029712064).

Almost surely, 2^{1666487623680} is an apocalyptic number.

1666487623680 is a gapful number since it is divisible by the number (10) 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 1666487623680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3379966507008).

1666487623680 is an abundant number, since it is smaller than the sum of its proper divisors (5093445390336).

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

1666487623680 is an equidigital number, since it uses as much as digits as its factorization.

1666487623680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579 (or 543 counting only the distinct ones).

The product of its (nonzero) digits is 83607552, while the sum is 63.

The spelling of 1666487623680 in words is "one trillion, six hundred sixty-six billion, four hundred eighty-seven million, six hundred twenty-three thousand, six hundred eighty".