1668365457781 has 8 divisors (see below), whose sum is σ = 1829180952000. Its totient is φ = 1509074281440.

The previous prime is 1668365457767. The next prime is 1668365457791. The reversal of 1668365457781 is 1877545638661.

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

It is not a de Polignac number, because 1668365457781 - 2⁷ = 1668365457653 is a prime.

It is a super-2 number, since 2×1668365457781² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668365457791) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 381077176 + ... + 381081553.

It is an arithmetic number, because the mean of its divisors is an integer number (228647619000).

Almost surely, 2^{1668365457781} is an apocalyptic number.

1668365457781 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1668365457781 is a deficient number, since it is larger than the sum of its proper divisors (160815494219).

1668365457781 is a wasteful number, since it uses less digits than its factorization.

1668365457781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 762158939.

The product of its digits is 203212800, while the sum is 67.

The spelling of 1668365457781 in words is "one trillion, six hundred sixty-eight billion, three hundred sixty-five million, four hundred fifty-seven thousand, seven hundred eighty-one".