1666681894783 has 8 divisors (see below), whose sum is σ = 1667552141808. Its totient is φ = 1665811839744.

The previous prime is 1666681894753. The next prime is 1666681894811. The reversal of 1666681894783 is 3874981866661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1666681894783 - 2²⁵ = 1666648340351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666681894753) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19311535 + ... + 19397647.

It is an arithmetic number, because the mean of its divisors is an integer number (208444017726).

Almost surely, 2^{1666681894783} is an apocalyptic number.

1666681894783 is a deficient number, since it is larger than the sum of its proper divisors (870247025).

1666681894783 is an equidigital number, since it uses as much as digits as its factorization.

1666681894783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95993.

The product of its digits is 501645312, while the sum is 73.

The spelling of 1666681894783 in words is "one trillion, six hundred sixty-six billion, six hundred eighty-one million, eight hundred ninety-four thousand, seven hundred eighty-three".