647640166 has 8 divisors (see below), whose sum is σ = 992129760. Its totient is φ = 316930248.

The previous prime is 647640163. The next prime is 647640173. The reversal of 647640166 is 661046746.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647640163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3444801 + ... + 3444988.

It is an arithmetic number, because the mean of its divisors is an integer number (124016220).

Almost surely, 2^647640166 is an apocalyptic number.

647640166 is a deficient number, since it is larger than the sum of its proper divisors (344489594).

647640166 is a wasteful number, since it uses less digits than its factorization.

647640166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6889838.

The product of its (nonzero) digits is 145152, while the sum is 40.

The square root of 647640166 is about 25448.7753339920. The cubic root of 647640166 is about 865.1895364675.

The spelling of 647640166 in words is "six hundred forty-seven million, six hundred forty thousand, one hundred sixty-six".