640040006 has 4 divisors (see below), whose sum is σ = 960060012. Its totient is φ = 320020002.

The previous prime is 640040003. The next prime is 640040017. The reversal of 640040006 is 600040046.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 600040046 = 2 ⋅300020023.

It is a self number, because there is not a number n which added to its sum of digits gives 640040006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640040003) 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 as a sum of consecutive naturals, namely, 160010000 + ... + 160010003.

It is an arithmetic number, because the mean of its divisors is an integer number (240015003).

Almost surely, 2^640040006 is an apocalyptic number.

640040006 is a deficient number, since it is larger than the sum of its proper divisors (320020006).

640040006 is a wasteful number, since it uses less digits than its factorization.

640040006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320020005.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 640040006 is about 25299.0119569915. The cubic root of 640040006 is about 861.7918319541.

The spelling of 640040006 in words is "six hundred forty million, forty thousand, six".