644829043 has 2 divisors, whose sum is σ = 644829044. Its totient is φ = 644829042.

The previous prime is 644829001. The next prime is 644829071. The reversal of 644829043 is 340928446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644829043 - 2¹³ = 644820851 is a prime.

It is a super-3 number, since 3×644829043³ (a number of 27 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644828987 and 644829005.

It is not a weakly prime, because it can be changed into another prime (644829083) 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, 322414521 + 322414522.

It is an arithmetic number, because the mean of its divisors is an integer number (322414522).

Almost surely, 2^644829043 is an apocalyptic number.

644829043 is a deficient number, since it is larger than the sum of its proper divisors (1).

644829043 is an equidigital number, since it uses as much as digits as its factorization.

644829043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 165888, while the sum is 40.

The square root of 644829043 is about 25393.4842627001. The cubic root of 644829043 is about 863.9359176544.

The spelling of 644829043 in words is "six hundred forty-four million, eight hundred twenty-nine thousand, forty-three".