1665315389 has 4 divisors (see below), whose sum is σ = 1666115424. Its totient is φ = 1664515356.

The previous prime is 1665315373. The next prime is 1665315451. The reversal of 1665315389 is 9835135661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1665315389 - 2⁴ = 1665315373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665315349) 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, 396887 + ... + 401060.

It is an arithmetic number, because the mean of its divisors is an integer number (416528856).

Almost surely, 2^1665315389 is an apocalyptic number.

It is an amenable number.

1665315389 is a deficient number, since it is larger than the sum of its proper divisors (800035).

1665315389 is an equidigital number, since it uses as much as digits as its factorization.

1665315389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800034.

The product of its digits is 583200, while the sum is 47.

The square root of 1665315389 is about 40808.2759866182. The cubic root of 1665315389 is about 1185.3105914958.

The spelling of 1665315389 in words is "one billion, six hundred sixty-five million, three hundred fifteen thousand, three hundred eighty-nine".