644046127 has 2 divisors, whose sum is σ = 644046128. Its totient is φ = 644046126.

The previous prime is 644046121. The next prime is 644046149. The reversal of 644046127 is 721640446.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 644046127 - 2³ = 644046119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644046092 and 644046101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644046121) 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, 322023063 + 322023064.

It is an arithmetic number, because the mean of its divisors is an integer number (322023064).

Almost surely, 2^644046127 is an apocalyptic number.

644046127 is a deficient number, since it is larger than the sum of its proper divisors (1).

644046127 is an equidigital number, since it uses as much as digits as its factorization.

644046127 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32256, while the sum is 34.

The square root of 644046127 is about 25378.0638938434. The cubic root of 644046127 is about 863.5861282077.

The spelling of 644046127 in words is "six hundred forty-four million, forty-six thousand, one hundred twenty-seven".