643254853 has 2 divisors, whose sum is σ = 643254854. Its totient is φ = 643254852.

The previous prime is 643254851. The next prime is 643254881. The reversal of 643254853 is 358452346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 462164004 + 181090849 = 21498^2 + 13457^2 .

It is a cyclic number.

It is not a de Polignac number, because 643254853 - 2¹ = 643254851 is a prime.

Together with 643254851, 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 (643254851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321627426 + 321627427.

It is an arithmetic number, because the mean of its divisors is an integer number (321627427).

Almost surely, 2^643254853 is an apocalyptic number.

It is an amenable number.

643254853 is a deficient number, since it is larger than the sum of its proper divisors (1).

643254853 is an equidigital number, since it uses as much as digits as its factorization.

643254853 is an evil number, because the sum of its binary digits is even.

The product of its digits is 345600, while the sum is 40.

The square root of 643254853 is about 25362.4693789860. The cubic root of 643254853 is about 863.2323164439.

The spelling of 643254853 in words is "six hundred forty-three million, two hundred fifty-four thousand, eight hundred fifty-three".