1665386747 has 4 divisors (see below), whose sum is σ = 1671719280. Its totient is φ = 1659054216.

The previous prime is 1665386719. The next prime is 1665386777. The reversal of 1665386747 is 7476835661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1665386747 - 2¹⁰ = 1665385723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1665386777) 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, 3165872 + ... + 3166397.

It is an arithmetic number, because the mean of its divisors is an integer number (417929820).

Almost surely, 2^1665386747 is an apocalyptic number.

1665386747 is a deficient number, since it is larger than the sum of its proper divisors (6332533).

1665386747 is an equidigital number, since it uses as much as digits as its factorization.

1665386747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6332532.

The product of its digits is 5080320, while the sum is 53.

The square root of 1665386747 is about 40809.1502851995. The cubic root of 1665386747 is about 1185.3275212589.

The spelling of 1665386747 in words is "one billion, six hundred sixty-five million, three hundred eighty-six thousand, seven hundred forty-seven".