640393603 has 2 divisors, whose sum is σ = 640393604. Its totient is φ = 640393602.

The previous prime is 640393601. The next prime is 640393657. The reversal of 640393603 is 306393046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640393603 - 2¹ = 640393601 is a prime.

Together with 640393601, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (640393601) 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, 320196801 + 320196802.

It is an arithmetic number, because the mean of its divisors is an integer number (320196802).

Almost surely, 2^640393603 is an apocalyptic number.

640393603 is a deficient number, since it is larger than the sum of its proper divisors (1).

640393603 is an equidigital number, since it uses as much as digits as its factorization.

640393603 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34992, while the sum is 34.

The square root of 640393603 is about 25305.9993479807. Note that the first 3 decimals coincide. The cubic root of 640393603 is about 861.9505047996.

The spelling of 640393603 in words is "six hundred forty million, three hundred ninety-three thousand, six hundred three".