640308353 has 2 divisors, whose sum is σ = 640308354. Its totient is φ = 640308352.

The previous prime is 640308337. The next prime is 640308359. The reversal of 640308353 is 353803046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 633428224 + 6880129 = 25168^2 + 2623^2 .

It is a cyclic number.

It is not a de Polignac number, because 640308353 - 2⁴ = 640308337 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (640308359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320154176 + 320154177.

It is an arithmetic number, because the mean of its divisors is an integer number (320154177).

Almost surely, 2^640308353 is an apocalyptic number.

It is an amenable number.

640308353 is a deficient number, since it is larger than the sum of its proper divisors (1).

640308353 is an equidigital number, since it uses as much as digits as its factorization.

640308353 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 32.

The square root of 640308353 is about 25304.3149087265. The cubic root of 640308353 is about 861.9122551247.

The spelling of 640308353 in words is "six hundred forty million, three hundred eight thousand, three hundred fifty-three".