1665747365 has 4 divisors (see below), whose sum is σ = 1998896844. Its totient is φ = 1332597888.

The previous prime is 1665747353. The next prime is 1665747371. The reversal of 1665747365 is 5637475661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5637475661 = 3917 ⋅1439233.

It can be written as a sum of positive squares in 2 ways, for example, as 289782529 + 1375964836 = 17023^2 + 37094^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665747365 - 2¹² = 1665743269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166574732 + ... + 166574741.

It is an arithmetic number, because the mean of its divisors is an integer number (499724211).

Almost surely, 2^1665747365 is an apocalyptic number.

It is an amenable number.

1665747365 is a deficient number, since it is larger than the sum of its proper divisors (333149479).

1665747365 is an equidigital number, since it uses as much as digits as its factorization.

1665747365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333149478.

The product of its digits is 3175200, while the sum is 50.

The square root of 1665747365 is about 40813.5683933664. The cubic root of 1665747365 is about 1185.4130708751.

The spelling of 1665747365 in words is "one billion, six hundred sixty-five million, seven hundred forty-seven thousand, three hundred sixty-five".