640211399 has 2 divisors, whose sum is σ = 640211400. Its totient is φ = 640211398.

The previous prime is 640211267. The next prime is 640211401. The reversal of 640211399 is 993112046.

640211399 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640211399 is a prime.

It is a Sophie Germain prime.

Together with 640211401, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640216399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320105699 + 320105700.

It is an arithmetic number, because the mean of its divisors is an integer number (320105700).

Almost surely, 2^640211399 is an apocalyptic number.

640211399 is a deficient number, since it is larger than the sum of its proper divisors (1).

640211399 is an equidigital number, since it uses as much as digits as its factorization.

640211399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 640211399 is about 25302.3990759770. The cubic root of 640211399 is about 861.8687500132.

The spelling of 640211399 in words is "six hundred forty million, two hundred eleven thousand, three hundred ninety-nine".