664799547 has 4 divisors (see below), whose sum is σ = 886399400. Its totient is φ = 443199696.

The previous prime is 664799519. The next prime is 664799573. The reversal of 664799547 is 745997466.

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

It is not a de Polignac number, because 664799547 - 2⁷ = 664799419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664799347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110799922 + ... + 110799927.

It is an arithmetic number, because the mean of its divisors is an integer number (221599850).

Almost surely, 2^664799547 is an apocalyptic number.

664799547 is a deficient number, since it is larger than the sum of its proper divisors (221599853).

664799547 is a wasteful number, since it uses less digits than its factorization.

664799547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221599852.

The product of its digits is 11430720, while the sum is 57.

The square root of 664799547 is about 25783.7070065575. The cubic root of 664799547 is about 872.7641625614.

The spelling of 664799547 in words is "six hundred sixty-four million, seven hundred ninety-nine thousand, five hundred forty-seven".