643679227 has 2 divisors, whose sum is σ = 643679228. Its totient is φ = 643679226.

The previous prime is 643679191. The next prime is 643679233. The reversal of 643679227 is 722976346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643679227 - 2²⁷ = 509461499 is a prime.

It is not a weakly prime, because it can be changed into another prime (643679237) 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, 321839613 + 321839614.

It is an arithmetic number, because the mean of its divisors is an integer number (321839614).

Almost surely, 2^643679227 is an apocalyptic number.

643679227 is a deficient number, since it is larger than the sum of its proper divisors (1).

643679227 is an equidigital number, since it uses as much as digits as its factorization.

643679227 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 46.

The square root of 643679227 is about 25370.8341802157. The cubic root of 643679227 is about 863.4221078972.

The spelling of 643679227 in words is "six hundred forty-three million, six hundred seventy-nine thousand, two hundred twenty-seven".