1666666668519 has 12 divisors (see below), whose sum is σ = 2407419729000. Its totient is φ = 1111105426704.

The previous prime is 1666666668503. The next prime is 1666666668553. The reversal of 1666666668519 is 9158666666661.

It is not a de Polignac number, because 1666666668519 - 2⁴ = 1666666668503 is a prime.

It is a super-2 number, since 2×1666666668519² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666666668559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2143912 + ... + 2815970.

It is an arithmetic number, because the mean of its divisors is an integer number (200618310750).

Almost surely, 2^{1666666668519} is an apocalyptic number.

1666666668519 is a deficient number, since it is larger than the sum of its proper divisors (740753060481).

1666666668519 is a wasteful number, since it uses less digits than its factorization.

1666666668519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 947614 (or 947611 counting only the distinct ones).

The product of its digits is 604661760, while the sum is 72.

The spelling of 1666666668519 in words is "one trillion, six hundred sixty-six billion, six hundred sixty-six million, six hundred sixty-eight thousand, five hundred nineteen".