640354206 has 8 divisors (see below), whose sum is σ = 1280708424. Its totient is φ = 213451400.

The previous prime is 640354177. The next prime is 640354243. The reversal of 640354206 is 602453046.

640354206 is nontrivially palindromic in base 7.

640354206 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

640354206 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53362845 + ... + 53362856.

It is an arithmetic number, because the mean of its divisors is an integer number (160088553).

Almost surely, 2^640354206 is an apocalyptic number.

640354206 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640354206 is a wasteful number, since it uses less digits than its factorization.

640354206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106725706.

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 640354206 is about 25305.2209237541. The cubic root of 640354206 is about 861.9328287119.

The spelling of 640354206 in words is "six hundred forty million, three hundred fifty-four thousand, two hundred six".