644052679 has 2 divisors, whose sum is σ = 644052680. Its totient is φ = 644052678.

The previous prime is 644052637. The next prime is 644052713. The reversal of 644052679 is 976250446.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644052679 - 2¹³ = 644044487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644053679) 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, 322026339 + 322026340.

It is an arithmetic number, because the mean of its divisors is an integer number (322026340).

Almost surely, 2^644052679 is an apocalyptic number.

644052679 is a deficient number, since it is larger than the sum of its proper divisors (1).

644052679 is an equidigital number, since it uses as much as digits as its factorization.

644052679 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 43.

The square root of 644052679 is about 25378.1929813767. The cubic root of 644052679 is about 863.5890566714.

The spelling of 644052679 in words is "six hundred forty-four million, fifty-two thousand, six hundred seventy-nine".