641680393 has 2 divisors, whose sum is σ = 641680394. Its totient is φ = 641680392.

The previous prime is 641680363. The next prime is 641680447. The reversal of 641680393 is 393086146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 402885184 + 238795209 = 20072^2 + 15453^2 .

It is a cyclic number.

It is not a de Polignac number, because 641680393 - 2¹³ = 641672201 is a prime.

It is not a weakly prime, because it can be changed into another prime (641680343) 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, 320840196 + 320840197.

It is an arithmetic number, because the mean of its divisors is an integer number (320840197).

Almost surely, 2^641680393 is an apocalyptic number.

It is an amenable number.

641680393 is a deficient number, since it is larger than the sum of its proper divisors (1).

641680393 is an equidigital number, since it uses as much as digits as its factorization.

641680393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 641680393 is about 25331.4111924306. The cubic root of 641680393 is about 862.5274454055.

The spelling of 641680393 in words is "six hundred forty-one million, six hundred eighty thousand, three hundred ninety-three".