644235107 has 2 divisors, whose sum is σ = 644235108. Its totient is φ = 644235106.

The previous prime is 644235079. The next prime is 644235121. The reversal of 644235107 is 701532446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644235107 - 2¹² = 644231011 is a prime.

It is not a weakly prime, because it can be changed into another prime (644235167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322117553 + 322117554.

It is an arithmetic number, because the mean of its divisors is an integer number (322117554).

Almost surely, 2^644235107 is an apocalyptic number.

644235107 is a deficient number, since it is larger than the sum of its proper divisors (1).

644235107 is an equidigital number, since it uses as much as digits as its factorization.

644235107 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 644235107 is about 25381.7869150302. The cubic root of 644235107 is about 863.6705862094.

The spelling of 644235107 in words is "six hundred forty-four million, two hundred thirty-five thousand, one hundred seven".