640546853 has 2 divisors, whose sum is σ = 640546854. Its totient is φ = 640546852.

The previous prime is 640546843. The next prime is 640546861. The reversal of 640546853 is 358645046.

640546853 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 can be written as a sum of positive squares in only one way, i.e., 481231969 + 159314884 = 21937^2 + 12622^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640546853 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 640546853.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640546843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320273426 + 320273427.

It is an arithmetic number, because the mean of its divisors is an integer number (320273427).

Almost surely, 2^640546853 is an apocalyptic number.

It is an amenable number.

640546853 is a deficient number, since it is larger than the sum of its proper divisors (1).

640546853 is an equidigital number, since it uses as much as digits as its factorization.

640546853 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 345600, while the sum is 41.

The square root of 640546853 is about 25309.0271049679. The cubic root of 640546853 is about 862.0192559441.

It can be divided in two parts, 64054 and 6853, that added together give a palindrome (70907).

The spelling of 640546853 in words is "six hundred forty million, five hundred forty-six thousand, eight hundred fifty-three".