664669121217 has 12 divisors (see below), whose sum is σ = 941422931856. Its totient is φ = 417047291200.

The previous prime is 664669121177. The next prime is 664669121231. The reversal of 664669121217 is 712121966466.

It is a happy number.

664669121217 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 664669121217 - 2¹⁸ = 664668859073 is a prime.

It is a super-2 number, since 2×664669121217² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a self number, because there is not a number n which added to its sum of digits gives 664669121217.

It is not an unprimeable number, because it can be changed into a prime (664669121717) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 383314659 + ... + 383316392.

It is an arithmetic number, because the mean of its divisors is an integer number (78451910988).

Almost surely, 2^664669121217 is an apocalyptic number.

It is an amenable number.

664669121217 is a deficient number, since it is larger than the sum of its proper divisors (276753810639).

664669121217 is a wasteful number, since it uses less digits than its factorization.

664669121217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 766631088 (or 766631071 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 51.

The spelling of 664669121217 in words is "six hundred sixty-four billion, six hundred sixty-nine million, one hundred twenty-one thousand, two hundred seventeen".