644076133 has 2 divisors, whose sum is σ = 644076134. Its totient is φ = 644076132.

The previous prime is 644076113. The next prime is 644076151. The reversal of 644076133 is 331670446.

644076133 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 575136324 + 68939809 = 23982^2 + 8303^2 .

It is a cyclic number.

It is not a de Polignac number, because 644076133 - 2⁵ = 644076101 is a prime.

It is a super-3 number, since 3×644076133³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644076113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322038066 + 322038067.

It is an arithmetic number, because the mean of its divisors is an integer number (322038067).

Almost surely, 2^644076133 is an apocalyptic number.

It is an amenable number.

644076133 is a deficient number, since it is larger than the sum of its proper divisors (1).

644076133 is an equidigital number, since it uses as much as digits as its factorization.

644076133 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 34.

The square root of 644076133 is about 25378.6550668076. The cubic root of 644076133 is about 863.5995394432.

The spelling of 644076133 in words is "six hundred forty-four million, seventy-six thousand, one hundred thirty-three".