1666326313 has 4 divisors (see below), whose sum is σ = 1666434820. Its totient is φ = 1666217808.

The previous prime is 1666326289. The next prime is 1666326317. The reversal of 1666326313 is 3136236661.

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 can be written as a sum of positive squares in 2 ways, for example, as 396686889 + 1269639424 = 19917^2 + 35632^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666326313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666326317) 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, 26478 + ... + 63511.

It is an arithmetic number, because the mean of its divisors is an integer number (416608705).

Almost surely, 2^1666326313 is an apocalyptic number.

It is an amenable number.

1666326313 is a deficient number, since it is larger than the sum of its proper divisors (108507).

1666326313 is an equidigital number, since it uses as much as digits as its factorization.

1666326313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108506.

The product of its digits is 69984, while the sum is 37.

The square root of 1666326313 is about 40820.6603694747. The cubic root of 1666326313 is about 1185.5503892238.

The spelling of 1666326313 in words is "one billion, six hundred sixty-six million, three hundred twenty-six thousand, three hundred thirteen".