665123537 has 8 divisors (see below), whose sum is σ = 722627304. Its totient is φ = 608525568.

The previous prime is 665123531. The next prime is 665123603. The reversal of 665123537 is 735321566.

It can be written as a sum of positive squares in 4 ways, for example, as 34058896 + 631064641 = 5836^2 + 25121^2 .

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 665123537 - 2⁸ = 665123281 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 665123537.

It is not an unprimeable number, because it can be changed into a prime (665123531) 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 7 ways as a sum of consecutive naturals, for example, 224918 + ... + 227855.

It is an arithmetic number, because the mean of its divisors is an integer number (90328413).

Almost surely, 2^665123537 is an apocalyptic number.

It is an amenable number.

665123537 is a deficient number, since it is larger than the sum of its proper divisors (57503767).

665123537 is a wasteful number, since it uses less digits than its factorization.

665123537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452899.

The product of its digits is 113400, while the sum is 38.

The square root of 665123537 is about 25789.9890849143. The cubic root of 665123537 is about 872.9059200476.

The spelling of 665123537 in words is "six hundred sixty-five million, one hundred twenty-three thousand, five hundred thirty-seven".