665241019 has 4 divisors (see below), whose sum is σ = 683220544. Its totient is φ = 647261496.

The previous prime is 665241013. The next prime is 665241023. The reversal of 665241019 is 910142566.

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

It is a cyclic number.

It is not a de Polignac number, because 665241019 - 2¹¹ = 665238971 is a prime.

It is a super-2 number, since 2×665241019² = 885091226720316722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665241013) 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, 8989707 + ... + 8989780.

It is an arithmetic number, because the mean of its divisors is an integer number (170805136).

Almost surely, 2^665241019 is an apocalyptic number.

665241019 is a deficient number, since it is larger than the sum of its proper divisors (17979525).

665241019 is a wasteful number, since it uses less digits than its factorization.

665241019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17979524.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 665241019 is about 25792.2666510720. The cubic root of 665241019 is about 872.9573113508.

The spelling of 665241019 in words is "six hundred sixty-five million, two hundred forty-one thousand, nineteen".