664907817 has 16 divisors (see below), whose sum is σ = 1016399232. Its totient is φ = 378744960.

The previous prime is 664907767. The next prime is 664907827. The reversal of 664907817 is 718709466.

It is not a de Polignac number, because 664907817 - 2¹⁴ = 664891433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (664907827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43284 + ... + 56597.

It is an arithmetic number, because the mean of its divisors is an integer number (63524952).

Almost surely, 2^664907817 is an apocalyptic number.

It is an amenable number.

664907817 is a deficient number, since it is larger than the sum of its proper divisors (351491415).

664907817 is a wasteful number, since it uses less digits than its factorization.

664907817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100208.

The product of its (nonzero) digits is 508032, while the sum is 48.

The square root of 664907817 is about 25785.8065028030. The cubic root of 664907817 is about 872.8115397730.

The spelling of 664907817 in words is "six hundred sixty-four million, nine hundred seven thousand, eight hundred seventeen".