1668890371 has 4 divisors (see below), whose sum is σ = 1669001544. Its totient is φ = 1668779200.

The previous prime is 1668890359. The next prime is 1668890381. The reversal of 1668890371 is 1730988661.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1668890371 - 2⁵ = 1668890339 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1668890381) 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 3 ways as a sum of consecutive naturals, for example, 28750 + ... + 64531.

It is an arithmetic number, because the mean of its divisors is an integer number (417250386).

Almost surely, 2^1668890371 is an apocalyptic number.

1668890371 is a deficient number, since it is larger than the sum of its proper divisors (111173).

1668890371 is an equidigital number, since it uses as much as digits as its factorization.

1668890371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111172.

The product of its (nonzero) digits is 435456, while the sum is 49.

The square root of 1668890371 is about 40852.0546729292. The cubic root of 1668890371 is about 1186.1581657627.

The spelling of 1668890371 in words is "one billion, six hundred sixty-eight million, eight hundred ninety thousand, three hundred seventy-one".