665498089 has 4 divisors (see below), whose sum is σ = 665587156. Its totient is φ = 665409024.

The previous prime is 665498081. The next prime is 665498131. The reversal of 665498089 is 980894566.

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 227014489 + 438483600 = 15067^2 + 20940^2 .

It is a cyclic number.

It is not a de Polignac number, because 665498089 - 2³ = 665498081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665498081) 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, 32184 + ... + 48649.

It is an arithmetic number, because the mean of its divisors is an integer number (166396789).

Almost surely, 2^665498089 is an apocalyptic number.

It is an amenable number.

665498089 is a deficient number, since it is larger than the sum of its proper divisors (89067).

665498089 is an equidigital number, since it uses as much as digits as its factorization.

665498089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89066.

The product of its (nonzero) digits is 3732480, while the sum is 55.

The square root of 665498089 is about 25797.2496402233. The cubic root of 665498089 is about 873.0697429003.

The spelling of 665498089 in words is "six hundred sixty-five million, four hundred ninety-eight thousand, eighty-nine".