1648568665 has 4 divisors (see below), whose sum is σ = 1978282404. Its totient is φ = 1318854928.

The previous prime is 1648568653. The next prime is 1648568671. The reversal of 1648568665 is 5668658461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5668658461 = 9281 ⋅610781.

It can be written as a sum of positive squares in 2 ways, for example, as 183439936 + 1465128729 = 13544^2 + 38277^2 .

It is a cyclic number.

It is not a de Polignac number, because 1648568665 - 2¹¹ = 1648566617 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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164856862 + ... + 164856871.

It is an arithmetic number, because the mean of its divisors is an integer number (494570601).

Almost surely, 2^1648568665 is an apocalyptic number.

It is an amenable number.

1648568665 is a deficient number, since it is larger than the sum of its proper divisors (329713739).

1648568665 is an equidigital number, since it uses as much as digits as its factorization.

1648568665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329713738.

The product of its digits is 8294400, while the sum is 55.

The square root of 1648568665 is about 40602.5696846887. The cubic root of 1648568665 is about 1181.3239628202.

The spelling of 1648568665 in words is "one billion, six hundred forty-eight million, five hundred sixty-eight thousand, six hundred sixty-five".