665616447 has 20 divisors (see below), whose sum is σ = 997175520. Its totient is φ = 442468224.

The previous prime is 665616359. The next prime is 665616461. The reversal of 665616447 is 744616566.

665616447 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 665616447 - 2⁸ = 665616191 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665616467) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 16954 + ... + 40232.

It is an arithmetic number, because the mean of its divisors is an integer number (49858776).

Almost surely, 2^665616447 is an apocalyptic number.

665616447 is a deficient number, since it is larger than the sum of its proper divisors (331559073).

665616447 is a wasteful number, since it uses less digits than its factorization.

665616447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23644 (or 23635 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 665616447 is about 25799.5435424738. The cubic root of 665616447 is about 873.1214979516.

The spelling of 665616447 in words is "six hundred sixty-five million, six hundred sixteen thousand, four hundred forty-seven".