664811706 has 16 divisors (see below), whose sum is σ = 1431902304. Its totient is φ = 204557424.

The previous prime is 664811699. The next prime is 664811717. The reversal of 664811706 is 607118466.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4261536 + ... + 4261691.

It is an arithmetic number, because the mean of its divisors is an integer number (89493894).

Almost surely, 2^664811706 is an apocalyptic number.

664811706 is an abundant number, since it is smaller than the sum of its proper divisors (767090598).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664811706 is a wasteful number, since it uses less digits than its factorization.

664811706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8523245.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 664811706 is about 25783.9427939173. The cubic root of 664811706 is about 872.7694834007.

The spelling of 664811706 in words is "six hundred sixty-four million, eight hundred eleven thousand, seven hundred six".