665664218264 has 32 divisors (see below), whose sum is σ = 1314472756800. Its totient is φ = 315155797920.

The previous prime is 665664218239. The next prime is 665664218267. The reversal of 665664218264 is 462812466566.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665664218267) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 799982 + ... + 1404029.

It is an arithmetic number, because the mean of its divisors is an integer number (41077273650).

Almost surely, 2^665664218264 is an apocalyptic number.

It is an amenable number.

665664218264 is a deficient number, since it is larger than the sum of its proper divisors (648808538536).

665664218264 is a wasteful number, since it uses less digits than its factorization.

665664218264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2206023 (or 2206019 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 56.

The spelling of 665664218264 in words is "six hundred sixty-five billion, six hundred sixty-four million, two hundred eighteen thousand, two hundred sixty-four".