1668805091 has 8 divisors (see below), whose sum is σ = 1689303600. Its totient is φ = 1648345600.

The previous prime is 1668805079. The next prime is 1668805109. The reversal of 1668805091 is 1905088661.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1668805091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1668804091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81491 + ... + 99891.

It is an arithmetic number, because the mean of its divisors is an integer number (211162950).

Almost surely, 2^1668805091 is an apocalyptic number.

1668805091 is a deficient number, since it is larger than the sum of its proper divisors (20498509).

1668805091 is a wasteful number, since it uses less digits than its factorization.

1668805091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19509.

The product of its (nonzero) digits is 103680, while the sum is 44.

The square root of 1668805091 is about 40851.0108932447. The cubic root of 1668805091 is about 1186.1379612618.

The spelling of 1668805091 in words is "one billion, six hundred sixty-eight million, eight hundred five thousand, ninety-one".