1668444562779 has 4 divisors (see below), whose sum is σ = 2224592750376. Its totient is φ = 1112296375184.

The previous prime is 1668444562739. The next prime is 1668444562817. The reversal of 1668444562779 is 9772654448661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1668444562779 - 2¹⁹ = 1668444038491 is a prime.

It is a super-3 number, since 3×1668444562779³ (a number of 38 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1668444562709) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 278074093794 + ... + 278074093799.

It is an arithmetic number, because the mean of its divisors is an integer number (556148187594).

Almost surely, 2^{1668444562779} is an apocalyptic number.

1668444562779 is a deficient number, since it is larger than the sum of its proper divisors (556148187597).

1668444562779 is an equidigital number, since it uses as much as digits as its factorization.

1668444562779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556148187596.

The product of its digits is 487710720, while the sum is 69.

The spelling of 1668444562779 in words is "one trillion, six hundred sixty-eight billion, four hundred forty-four million, five hundred sixty-two thousand, seven hundred seventy-nine".