640394003 has 2 divisors, whose sum is σ = 640394004. Its totient is φ = 640394002.

The previous prime is 640393981. The next prime is 640394011. The reversal of 640394003 is 300493046.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640394003 - 2¹² = 640389907 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (640394203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320197001 + 320197002.

It is an arithmetic number, because the mean of its divisors is an integer number (320197002).

Almost surely, 2^640394003 is an apocalyptic number.

640394003 is a deficient number, since it is larger than the sum of its proper divisors (1).

640394003 is an equidigital number, since it uses as much as digits as its factorization.

640394003 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 29.

The square root of 640394003 is about 25306.0072512437. The cubic root of 640394003 is about 861.9506842622.

The spelling of 640394003 in words is "six hundred forty million, three hundred ninety-four thousand, three".