640264423 has 2 divisors, whose sum is σ = 640264424. Its totient is φ = 640264422.

The previous prime is 640264411. The next prime is 640264463. The reversal of 640264423 is 324462046.

640264423 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 a de Polignac number, because none of the positive numbers 2^k-640264423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640264463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320132211 + 320132212.

It is an arithmetic number, because the mean of its divisors is an integer number (320132212).

Almost surely, 2^640264423 is an apocalyptic number.

640264423 is a deficient number, since it is larger than the sum of its proper divisors (1).

640264423 is an equidigital number, since it uses as much as digits as its factorization.

640264423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 31.

The square root of 640264423 is about 25303.4468600624. The cubic root of 640264423 is about 861.8925434388.

The spelling of 640264423 in words is "six hundred forty million, two hundred sixty-four thousand, four hundred twenty-three".