664367647 has 4 divisors (see below), whose sum is σ = 671216896. Its totient is φ = 657518400.

The previous prime is 664367617. The next prime is 664367677. The reversal of 664367647 is 746763466.

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

It is an interprime number because it is at equal distance from previous prime (664367617) and next prime (664367677).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664367647 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 664367647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664367617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3424479 + ... + 3424672.

It is an arithmetic number, because the mean of its divisors is an integer number (167804224).

Almost surely, 2^664367647 is an apocalyptic number.

664367647 is a deficient number, since it is larger than the sum of its proper divisors (6849249).

664367647 is an equidigital number, since it uses as much as digits as its factorization.

664367647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6849248.

The product of its digits is 3048192, while the sum is 49.

The square root of 664367647 is about 25775.3302015706. The cubic root of 664367647 is about 872.5751188598.

The spelling of 664367647 in words is "six hundred sixty-four million, three hundred sixty-seven thousand, six hundred forty-seven".