641823397 has 2 divisors, whose sum is σ = 641823398. Its totient is φ = 641823396.

The previous prime is 641823383. The next prime is 641823407. The reversal of 641823397 is 793328146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 612760516 + 29062881 = 24754^2 + 5391^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641823397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641823317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320911698 + 320911699.

It is an arithmetic number, because the mean of its divisors is an integer number (320911699).

Almost surely, 2^641823397 is an apocalyptic number.

It is an amenable number.

641823397 is a deficient number, since it is larger than the sum of its proper divisors (1).

641823397 is an equidigital number, since it uses as much as digits as its factorization.

641823397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 43.

The square root of 641823397 is about 25334.2336967195. The cubic root of 641823397 is about 862.5915145352.

The spelling of 641823397 in words is "six hundred forty-one million, eight hundred twenty-three thousand, three hundred ninety-seven".