640417706 has 8 divisors (see below), whose sum is σ = 960891204. Its totient is φ = 320120640.

The previous prime is 640417703. The next prime is 640417717. The reversal of 640417706 is 607714046.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 631768225 + 8649481 = 25135^2 + 2941^2 .

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

It is not an unprimeable number, because it can be changed into a prime (640417703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34625 + ... + 49796.

Almost surely, 2^640417706 is an apocalyptic number.

640417706 is a deficient number, since it is larger than the sum of its proper divisors (320473498).

640417706 is a wasteful number, since it uses less digits than its factorization.

640417706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88216.

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 640417706 is about 25306.4755744454. The cubic root of 640417706 is about 861.9613186347.

The spelling of 640417706 in words is "six hundred forty million, four hundred seventeen thousand, seven hundred six".