644600741 has 2 divisors, whose sum is σ = 644600742. Its totient is φ = 644600740.

The previous prime is 644600687. The next prime is 644600753. The reversal of 644600741 is 147006446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 579798241 + 64802500 = 24079^2 + 8050^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644600741 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644600698 and 644600707.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644600141) 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, 322300370 + 322300371.

It is an arithmetic number, because the mean of its divisors is an integer number (322300371).

Almost surely, 2^644600741 is an apocalyptic number.

It is an amenable number.

644600741 is a deficient number, since it is larger than the sum of its proper divisors (1).

644600741 is an equidigital number, since it uses as much as digits as its factorization.

644600741 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 644600741 is about 25388.9885777279. The cubic root of 644600741 is about 863.8339466581.

The spelling of 644600741 in words is "six hundred forty-four million, six hundred thousand, seven hundred forty-one".