643775413 has 2 divisors, whose sum is σ = 643775414. Its totient is φ = 643775412.

The previous prime is 643775411. The next prime is 643775453. The reversal of 643775413 is 314577346.

It is an a-pointer prime, because the next prime (643775453) can be obtained adding 643775413 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 606784689 + 36990724 = 24633^2 + 6082^2 .

It is a cyclic number.

It is not a de Polignac number, because 643775413 - 2¹ = 643775411 is a prime.

Together with 643775411, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643775411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321887706 + 321887707.

It is an arithmetic number, because the mean of its divisors is an integer number (321887707).

Almost surely, 2^643775413 is an apocalyptic number.

It is an amenable number.

643775413 is a deficient number, since it is larger than the sum of its proper divisors (1).

643775413 is an equidigital number, since it uses as much as digits as its factorization.

643775413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 211680, while the sum is 40.

The square root of 643775413 is about 25372.7297112471. The cubic root of 643775413 is about 863.4651132634.

The spelling of 643775413 in words is "six hundred forty-three million, seven hundred seventy-five thousand, four hundred thirteen".