665243501 has 8 divisors (see below), whose sum is σ = 716791320. Its totient is φ = 613749312.

The previous prime is 665243489. The next prime is 665243521. The reversal of 665243501 is 105342566.

It can be written as a sum of positive squares in 4 ways, for example, as 47969476 + 617274025 = 6926^2 + 24845^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665243501 - 2¹⁴ = 665227117 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 (665243521) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 14531 + ... + 39263.

It is an arithmetic number, because the mean of its divisors is an integer number (89598915).

Almost surely, 2^665243501 is an apocalyptic number.

It is an amenable number.

665243501 is a deficient number, since it is larger than the sum of its proper divisors (51547819).

665243501 is a wasteful number, since it uses less digits than its factorization.

665243501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26815.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 665243501 is about 25792.3147662245. The cubic root of 665243501 is about 872.9583970111.

The spelling of 665243501 in words is "six hundred sixty-five million, two hundred forty-three thousand, five hundred one".