1668338661 has 8 divisors (see below), whose sum is σ = 2426674464. Its totient is φ = 1011114320.

The previous prime is 1668338657. The next prime is 1668338713.

1668338661 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1668338661 - 2² = 1668338657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1668338661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668338561) 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 7 ways as a sum of consecutive naturals, for example, 25277826 + ... + 25277891.

It is an arithmetic number, because the mean of its divisors is an integer number (303334308).

Almost surely, 2^1668338661 is an apocalyptic number.

1668338661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1668338661 is a deficient number, since it is larger than the sum of its proper divisors (758335803).

1668338661 is a wasteful number, since it uses less digits than its factorization.

1668338661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50555731.

The product of its digits is 746496, while the sum is 48.

The square root of 1668338661 is about 40845.3015780273. The cubic root of 1668338661 is about 1186.0274426868.

The spelling of 1668338661 in words is "one billion, six hundred sixty-eight million, three hundred thirty-eight thousand, six hundred sixty-one".