1666778340412 has 12 divisors (see below), whose sum is σ = 2917644751840. Its totient is φ = 833165554176.

The previous prime is 1666778340379. The next prime is 1666778340433. The reversal of 1666778340412 is 2140438776661.

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 55887237 + ... + 55917052.

Almost surely, 2^{1666778340412} is an apocalyptic number.

It is an amenable number.

1666778340412 is a deficient number, since it is larger than the sum of its proper divisors (1250866411428).

1666778340412 is a wasteful number, since it uses less digits than its factorization.

1666778340412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111808020 (or 111808018 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 55.

The spelling of 1666778340412 in words is "one trillion, six hundred sixty-six billion, seven hundred seventy-eight million, three hundred forty thousand, four hundred twelve".