1668786947 has 4 divisors (see below), whose sum is σ = 1722618816. Its totient is φ = 1614955080.

The previous prime is 1668786937. The next prime is 1668786949. The reversal of 1668786947 is 7496878661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7496878661 = 5869 ⋅1277369.

It is a cyclic number.

It is not a de Polignac number, because 1668786947 - 2¹² = 1668782851 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1668786947.

It is not an unprimeable number, because it can be changed into a prime (1668786949) 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, 26915888 + ... + 26915949.

It is an arithmetic number, because the mean of its divisors is an integer number (430654704).

Almost surely, 2^1668786947 is an apocalyptic number.

1668786947 is a deficient number, since it is larger than the sum of its proper divisors (53831869).

1668786947 is an equidigital number, since it uses as much as digits as its factorization.

1668786947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53831868.

The product of its digits is 24385536, while the sum is 62.

The square root of 1668786947 is about 40850.7888173533. The cubic root of 1668786947 is about 1186.1336625043.

The spelling of 1668786947 in words is "one billion, six hundred sixty-eight million, seven hundred eighty-six thousand, nine hundred forty-seven".