1665250313 has 4 divisors (see below), whose sum is σ = 1682417940. Its totient is φ = 1648082688.

The previous prime is 1665250297. The next prime is 1665250333. The reversal of 1665250313 is 3130525661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3130525661 = 3167 ⋅988483.

It can be written as a sum of positive squares in 2 ways, for example, as 1104365824 + 560884489 = 33232^2 + 23683^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665250313 - 2⁴ = 1665250297 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 1665250313.

It is not an unprimeable number, because it can be changed into a prime (1665250333) 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, 8583668 + ... + 8583861.

It is an arithmetic number, because the mean of its divisors is an integer number (420604485).

Almost surely, 2^1665250313 is an apocalyptic number.

It is an amenable number.

1665250313 is a deficient number, since it is larger than the sum of its proper divisors (17167627).

1665250313 is an equidigital number, since it uses as much as digits as its factorization.

1665250313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17167626.

The product of its (nonzero) digits is 16200, while the sum is 32.

The square root of 1665250313 is about 40807.4786405629. The cubic root of 1665250313 is about 1185.2951517224.

Adding to 1665250313 its reverse (3130525661), we get a palindrome (4795775974).

The spelling of 1665250313 in words is "one billion, six hundred sixty-five million, two hundred fifty thousand, three hundred thirteen".