644046269 has 2 divisors, whose sum is σ = 644046270. Its totient is φ = 644046268.

The previous prime is 644046259. The next prime is 644046307. The reversal of 644046269 is 962640446.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 394816900 + 249229369 = 19870^2 + 15787^2 .

It is a cyclic number.

It is not a de Polignac number, because 644046269 - 2¹² = 644042173 is a prime.

It is a super-2 number, since 2×644046269² = 829591193225640722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644046209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322023134 + 322023135.

It is an arithmetic number, because the mean of its divisors is an integer number (322023135).

Almost surely, 2^644046269 is an apocalyptic number.

It is an amenable number.

644046269 is a deficient number, since it is larger than the sum of its proper divisors (1).

644046269 is an equidigital number, since it uses as much as digits as its factorization.

644046269 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 41.

The square root of 644046269 is about 25378.0666915350. The cubic root of 644046269 is about 863.5861916758.

The spelling of 644046269 in words is "six hundred forty-four million, forty-six thousand, two hundred sixty-nine".