665405589 has 4 divisors (see below), whose sum is σ = 887207456. Its totient is φ = 443603724.

The previous prime is 665405581. The next prime is 665405597. The reversal of 665405589 is 985504566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (665405581) and next prime (665405597).

It is not a de Polignac number, because 665405589 - 2³ = 665405581 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 (665405581) 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, 110900929 + ... + 110900934.

It is an arithmetic number, because the mean of its divisors is an integer number (221801864).

Almost surely, 2^665405589 is an apocalyptic number.

It is an amenable number.

665405589 is a deficient number, since it is larger than the sum of its proper divisors (221801867).

665405589 is a wasteful number, since it uses less digits than its factorization.

665405589 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221801866.

The product of its (nonzero) digits is 1296000, while the sum is 48.

The square root of 665405589 is about 25795.4567511413. The cubic root of 665405589 is about 873.0292906463.

The spelling of 665405589 in words is "six hundred sixty-five million, four hundred five thousand, five hundred eighty-nine".