1668245310781 has 12 divisors (see below), whose sum is σ = 1969576252608. Its totient is φ = 1408582391832.

The previous prime is 1668245310769. The next prime is 1668245310821. The reversal of 1668245310781 is 1870135428661.

It is not a de Polignac number, because 1668245310781 - 2¹¹ = 1668245308733 is a prime.

It is a super-2 number, since 2×1668245310781² (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 (1668245310731) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 254070021 + ... + 254076586.

It is an arithmetic number, because the mean of its divisors is an integer number (164131354384).

Almost surely, 2^{1668245310781} is an apocalyptic number.

It is an amenable number.

1668245310781 is a deficient number, since it is larger than the sum of its proper divisors (301330941827).

1668245310781 is an equidigital number, since it uses as much as digits as its factorization.

1668245310781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508146688 (or 508146681 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 52.

The spelling of 1668245310781 in words is "one trillion, six hundred sixty-eight billion, two hundred forty-five million, three hundred ten thousand, seven hundred eighty-one".