645906227 has 2 divisors, whose sum is σ = 645906228. Its totient is φ = 645906226.

The previous prime is 645906223. The next prime is 645906253. The reversal of 645906227 is 722609546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645906227 - 2² = 645906223 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (645906223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322953113 + 322953114.

It is an arithmetic number, because the mean of its divisors is an integer number (322953114).

Almost surely, 2^645906227 is an apocalyptic number.

645906227 is a deficient number, since it is larger than the sum of its proper divisors (1).

645906227 is an equidigital number, since it uses as much as digits as its factorization.

645906227 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 41.

The square root of 645906227 is about 25414.6852626587. The cubic root of 645906227 is about 864.4167170437.

The spelling of 645906227 in words is "six hundred forty-five million, nine hundred six thousand, two hundred twenty-seven".