640871662 has 8 divisors (see below), whose sum is σ = 962242992. Its totient is φ = 320124000.

The previous prime is 640871657. The next prime is 640871663. The reversal of 640871662 is 266178046.

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 (640871663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 153339 + ... + 157462.

It is an arithmetic number, because the mean of its divisors is an integer number (120280374).

Almost surely, 2^640871662 is an apocalyptic number.

640871662 is a deficient number, since it is larger than the sum of its proper divisors (321371330).

640871662 is a wasteful number, since it uses less digits than its factorization.

640871662 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311834.

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 640871662 is about 25315.4431523527. The cubic root of 640871662 is about 862.1649357896.

The spelling of 640871662 in words is "six hundred forty million, eight hundred seventy-one thousand, six hundred sixty-two".