640456343 has 2 divisors, whose sum is σ = 640456344. Its totient is φ = 640456342.

The previous prime is 640456337. The next prime is 640456361. The reversal of 640456343 is 343654046.

640456343 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640456343 - 2⁶ = 640456279 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640456363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320228171 + 320228172.

It is an arithmetic number, because the mean of its divisors is an integer number (320228172).

Almost surely, 2^640456343 is an apocalyptic number.

640456343 is a deficient number, since it is larger than the sum of its proper divisors (1).

640456343 is an equidigital number, since it uses as much as digits as its factorization.

640456343 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 103680, while the sum is 35.

The square root of 640456343 is about 25307.2389446182. The cubic root of 640456343 is about 861.9786525973.

The spelling of 640456343 in words is "six hundred forty million, four hundred fifty-six thousand, three hundred forty-three".