644975183 has 2 divisors, whose sum is σ = 644975184. Its totient is φ = 644975182.

The previous prime is 644975117. The next prime is 644975203. The reversal of 644975183 is 381579446.

644975183 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 is a cyclic number.

It is not a de Polignac number, because 644975183 - 2¹⁴ = 644958799 is a prime.

It is a super-3 number, since 3×644975183³ (a number of 27 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644975483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322487591 + 322487592.

It is an arithmetic number, because the mean of its divisors is an integer number (322487592).

Almost surely, 2^644975183 is an apocalyptic number.

644975183 is a deficient number, since it is larger than the sum of its proper divisors (1).

644975183 is an equidigital number, since it uses as much as digits as its factorization.

644975183 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 725760, while the sum is 47.

The square root of 644975183 is about 25396.3616094904. The cubic root of 644975183 is about 864.0011783927.

The spelling of 644975183 in words is "six hundred forty-four million, nine hundred seventy-five thousand, one hundred eighty-three".