640005707 has 4 divisors (see below), whose sum is σ = 698188056. Its totient is φ = 581823360.

The previous prime is 640005703. The next prime is 640005719. The reversal of 640005707 is 707500046.

640005707 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 640005707 - 2² = 640005703 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640005707.

It is not an unprimeable number, because it can be changed into a prime (640005701) 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, 29091158 + ... + 29091179.

It is an arithmetic number, because the mean of its divisors is an integer number (174547014).

Almost surely, 2^640005707 is an apocalyptic number.

640005707 is a deficient number, since it is larger than the sum of its proper divisors (58182349).

640005707 is a wasteful number, since it uses less digits than its factorization.

640005707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58182348.

The product of its (nonzero) digits is 5880, while the sum is 29.

The square root of 640005707 is about 25298.3340755869. The cubic root of 640005707 is about 861.7764375382.

The spelling of 640005707 in words is "six hundred forty million, five thousand, seven hundred seven".