1668181506 has 8 divisors (see below), whose sum is σ = 3336363024. Its totient is φ = 556060500.

The previous prime is 1668181499. The next prime is 1668181507. The reversal of 1668181506 is 6051818661.

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

1668181506 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (1668181507) 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, 139015120 + ... + 139015131.

It is an arithmetic number, because the mean of its divisors is an integer number (417045378).

Almost surely, 2^1668181506 is an apocalyptic number.

1668181506 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1668181506 is a wasteful number, since it uses less digits than its factorization.

1668181506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278030256.

The product of its (nonzero) digits is 69120, while the sum is 42.

The square root of 1668181506 is about 40843.3777496426. The cubic root of 1668181506 is about 1185.9902008486.

The spelling of 1668181506 in words is "one billion, six hundred sixty-eight million, one hundred eighty-one thousand, five hundred six".