641082721 has 2 divisors, whose sum is σ = 641082722. Its totient is φ = 641082720.

The previous prime is 641082707. The next prime is 641082769. The reversal of 641082721 is 127280146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 452157696 + 188925025 = 21264^2 + 13745^2 .

It is a cyclic number.

It is not a de Polignac number, because 641082721 - 2¹¹ = 641080673 is a prime.

It is not a weakly prime, because it can be changed into another prime (641682721) 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, 320541360 + 320541361.

It is an arithmetic number, because the mean of its divisors is an integer number (320541361).

Almost surely, 2^641082721 is an apocalyptic number.

It is an amenable number.

641082721 is a deficient number, since it is larger than the sum of its proper divisors (1).

641082721 is an equidigital number, since it uses as much as digits as its factorization.

641082721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 641082721 is about 25319.6113911727. The cubic root of 641082721 is about 862.2595713241.

The spelling of 641082721 in words is "six hundred forty-one million, eighty-two thousand, seven hundred twenty-one".