665563590 has 48 divisors (see below), whose sum is σ = 1731738528. Its totient is φ = 177353088.

The previous prime is 665563579. The next prime is 665563681. The reversal of 665563590 is 95365566.

665563590 is a `hidden beast` number, since 6 + 6 + 5 + 5 + 635 + 9 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 238282 + ... + 241058.

It is an arithmetic number, because the mean of its divisors is an integer number (36077886).

Almost surely, 2^665563590 is an apocalyptic number.

665563590 is an abundant number, since it is smaller than the sum of its proper divisors (1066174938).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665563590 is a wasteful number, since it uses less digits than its factorization.

665563590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5453 (or 5450 counting only the distinct ones).

The product of its (nonzero) digits is 729000, while the sum is 45.

The square root of 665563590 is about 25798.5191435478. The cubic root of 665563590 is about 873.0983856398.

The spelling of 665563590 in words is "six hundred sixty-five million, five hundred sixty-three thousand, five hundred ninety".