644227 has 2 divisors, whose sum is σ = 644228. Its totient is φ = 644226.

The previous prime is 644201. The next prime is 644239. The reversal of 644227 is 722446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644227 - 2¹⁵ = 611459 is a prime.

It is not a weakly prime, because it can be changed into another prime (644257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322113 + 322114.

It is an arithmetic number, because the mean of its divisors is an integer number (322114).

2⁶⁴⁴²²⁷ is an apocalyptic number.

644227 is a deficient number, since it is larger than the sum of its proper divisors (1).

644227 is an equidigital number, since it uses as much as digits as its factorization.

644227 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 25.

The square root of 644227 is about 802.6375271566. The cubic root of 644227 is about 86.3666963408.

The spelling of 644227 in words is "six hundred forty-four thousand, two hundred twenty-seven".