643187 has 2 divisors, whose sum is σ = 643188. Its totient is φ = 643186.

The previous prime is 643183. The next prime is 643199. The reversal of 643187 is 781346.

643187 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643187 - 2² = 643183 is a prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 643187.

It is not a weakly prime, because it can be changed into another prime (643183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321593 + 321594.

It is an arithmetic number, because the mean of its divisors is an integer number (321594).

2⁶⁴³¹⁸⁷ is an apocalyptic number.

643187 is a deficient number, since it is larger than the sum of its proper divisors (1).

643187 is an equidigital number, since it uses as much as digits as its factorization.

643187 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 29.

The square root of 643187 is about 801.9894014262. The cubic root of 643187 is about 86.3201963020.

The spelling of 643187 in words is "six hundred forty-three thousand, one hundred eighty-seven".