664741973217 has 128 divisors (see below), whose sum is σ = 1098428108800. Its totient is φ = 349192166400.

The previous prime is 664741973131. The next prime is 664741973267. The reversal of 664741973217 is 712379147466.

664741973217 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 664741973217 - 2⁷ = 664741973089 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664741973267) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 878126403 + ... + 878127159.

It is an arithmetic number, because the mean of its divisors is an integer number (8581469600).

Almost surely, 2^664741973217 is an apocalyptic number.

It is an amenable number.

664741973217 is a deficient number, since it is larger than the sum of its proper divisors (433686135583).

664741973217 is a wasteful number, since it uses less digits than its factorization.

664741973217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1287.

The product of its digits is 10668672, while the sum is 57.

The spelling of 664741973217 in words is "six hundred sixty-four billion, seven hundred forty-one million, nine hundred seventy-three thousand, two hundred seventeen".