665263001 has 4 divisors (see below), whose sum is σ = 716437092. Its totient is φ = 614088912.

The previous prime is 665262991. The next prime is 665263003. The reversal of 665263001 is 100362566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 100362566 = 2 ⋅50181283.

It can be written as a sum of positive squares in 2 ways, for example, as 313325401 + 351937600 = 17701^2 + 18760^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665263001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665263003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25587026 + ... + 25587051.

It is an arithmetic number, because the mean of its divisors is an integer number (179109273).

Almost surely, 2^665263001 is an apocalyptic number.

It is an amenable number.

665263001 is a deficient number, since it is larger than the sum of its proper divisors (51174091).

665263001 is a wasteful number, since it uses less digits than its factorization.

665263001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51174090.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 665263001 is about 25792.6927830345. The cubic root of 665263001 is about 872.9669264806.

The spelling of 665263001 in words is "six hundred sixty-five million, two hundred sixty-three thousand, one".