665478407 has 4 divisors (see below), whose sum is σ = 725976456. Its totient is φ = 604980360.

The previous prime is 665478403. The next prime is 665478427. The reversal of 665478407 is 704874566.

It is a happy number.

665478407 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 665478407 - 2² = 665478403 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 (665478403) 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, 30249008 + ... + 30249029.

It is an arithmetic number, because the mean of its divisors is an integer number (181494114).

Almost surely, 2^665478407 is an apocalyptic number.

665478407 is a deficient number, since it is larger than the sum of its proper divisors (60498049).

665478407 is a wasteful number, since it uses less digits than its factorization.

665478407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60498048.

The product of its (nonzero) digits is 1128960, while the sum is 47.

The square root of 665478407 is about 25796.8681626278. The cubic root of 665478407 is about 873.0611358493.

The spelling of 665478407 in words is "six hundred sixty-five million, four hundred seventy-eight thousand, four hundred seven".