1650666565 has 4 divisors (see below), whose sum is σ = 1980799884. Its totient is φ = 1320533248.

The previous prime is 1650666547. The next prime is 1650666569. The reversal of 1650666565 is 5656660561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 968516641 + 682149924 = 31121^2 + 26118^2 .

It is a cyclic number.

It is not a de Polignac number, because 1650666565 - 2¹¹ = 1650664517 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 (1650666569) by changing a digit.

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, 165066652 + ... + 165066661.

It is an arithmetic number, because the mean of its divisors is an integer number (495199971).

Almost surely, 2^1650666565 is an apocalyptic number.

It is an amenable number.

1650666565 is a deficient number, since it is larger than the sum of its proper divisors (330133319).

1650666565 is an equidigital number, since it uses as much as digits as its factorization.

1650666565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330133318.

The product of its (nonzero) digits is 972000, while the sum is 46.

The square root of 1650666565 is about 40628.3960426695. The cubic root of 1650666565 is about 1181.8248516774.

The spelling of 1650666565 in words is "one billion, six hundred fifty million, six hundred sixty-six thousand, five hundred sixty-five".