641728369 has 2 divisors, whose sum is σ = 641728370. Its totient is φ = 641728368.

The previous prime is 641728343. The next prime is 641728387. The reversal of 641728369 is 963827146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 631868769 + 9859600 = 25137^2 + 3140^2 .

It is a cyclic number.

It is not a de Polignac number, because 641728369 - 2⁹ = 641727857 is a prime.

It is a super-2 number, since 2×641728369² = 823630599158800322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (641728169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320864184 + 320864185.

It is an arithmetic number, because the mean of its divisors is an integer number (320864185).

Almost surely, 2^641728369 is an apocalyptic number.

It is an amenable number.

641728369 is a deficient number, since it is larger than the sum of its proper divisors (1).

641728369 is an equidigital number, since it uses as much as digits as its factorization.

641728369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 46.

The square root of 641728369 is about 25332.3581413180. The cubic root of 641728369 is about 862.5489408342.

It can be divided in two parts, 641728 and 369, that multiplied together give a palindrome (236797632).

The spelling of 641728369 in words is "six hundred forty-one million, seven hundred twenty-eight thousand, three hundred sixty-nine".