664016646021 has 16 divisors (see below), whose sum is σ = 887029200768. Its totient is φ = 441841435200.

The previous prime is 664016645987. The next prime is 664016646031. The reversal of 664016646021 is 120646610466.

It is not a de Polignac number, because 664016646021 - 2¹⁰ = 664016644997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664016646031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5314155 + ... + 5437671.

It is an arithmetic number, because the mean of its divisors is an integer number (55439325048).

Almost surely, 2^664016646021 is an apocalyptic number.

It is an amenable number.

664016646021 is a deficient number, since it is larger than the sum of its proper divisors (223012554747).

664016646021 is a wasteful number, since it uses less digits than its factorization.

664016646021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126892.

The product of its (nonzero) digits is 248832, while the sum is 42.

The spelling of 664016646021 in words is "six hundred sixty-four billion, sixteen million, six hundred forty-six thousand, twenty-one".