1668854779 has 4 divisors (see below), whose sum is σ = 1669066000. Its totient is φ = 1668643560.

The previous prime is 1668854773. The next prime is 1668854783. The reversal of 1668854779 is 9774588661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9774588661 = 67 ⋅145889383.

It is a cyclic number.

It is not a de Polignac number, because 1668854779 - 2⁹ = 1668854267 is a prime.

It is a super-2 number, since 2×1668854779² = 5570152546782277682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1668854773) 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, 93279 + ... + 109720.

It is an arithmetic number, because the mean of its divisors is an integer number (417266500).

Almost surely, 2^1668854779 is an apocalyptic number.

1668854779 is a deficient number, since it is larger than the sum of its proper divisors (211221).

1668854779 is an equidigital number, since it uses as much as digits as its factorization.

1668854779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211220.

The product of its digits is 20321280, while the sum is 61.

The square root of 1668854779 is about 40851.6190499226. The cubic root of 1668854779 is about 1186.1497334051.

The spelling of 1668854779 in words is "one billion, six hundred sixty-eight million, eight hundred fifty-four thousand, seven hundred seventy-nine".