664620447 has 8 divisors (see below), whose sum is σ = 886748544. Its totient is φ = 442786328.

The previous prime is 664620431. The next prime is 664620449. The reversal of 664620447 is 744026466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 664620447 - 2⁴ = 664620431 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664620449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68163 + ... + 77300.

It is an arithmetic number, because the mean of its divisors is an integer number (110843568).

Almost surely, 2^664620447 is an apocalyptic number.

664620447 is a deficient number, since it is larger than the sum of its proper divisors (222128097).

664620447 is a wasteful number, since it uses less digits than its factorization.

664620447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146989.

The product of its (nonzero) digits is 193536, while the sum is 39.

The square root of 664620447 is about 25780.2336490576. The cubic root of 664620447 is about 872.6857799866.

The spelling of 664620447 in words is "six hundred sixty-four million, six hundred twenty thousand, four hundred forty-seven".