1601151665 has 4 divisors (see below), whose sum is σ = 1921382004. Its totient is φ = 1280921328.

The previous prime is 1601151659. The next prime is 1601151689. The reversal of 1601151665 is 5661511061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5661511061 = 5279 ⋅1072459.

It can be written as a sum of positive squares in 2 ways, for example, as 1221642304 + 379509361 = 34952^2 + 19481^2 .

It is a cyclic number.

It is not a de Polignac number, because 1601151665 - 2²⁶ = 1534042801 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160115162 + ... + 160115171.

It is an arithmetic number, because the mean of its divisors is an integer number (480345501).

Almost surely, 2^1601151665 is an apocalyptic number.

It is an amenable number.

1601151665 is a deficient number, since it is larger than the sum of its proper divisors (320230339).

1601151665 is an equidigital number, since it uses as much as digits as its factorization.

1601151665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320230338.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 1601151665 is about 40014.3932229392. The cubic root of 1601151665 is about 1169.8876520559.

It can be divided in two parts, 16011 and 51665, that added together give a palindrome (67676).

The spelling of 1601151665 in words is "one billion, six hundred one million, one hundred fifty-one thousand, six hundred sixty-five".