641640001 has 2 divisors, whose sum is σ = 641640002. Its totient is φ = 641640000.

The previous prime is 641639989. The next prime is 641640019. The reversal of 641640001 is 100046146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 570254400 + 71385601 = 23880^2 + 8449^2 .

It is a cyclic number.

It is not a de Polignac number, because 641640001 - 2¹⁷ = 641508929 is a prime.

It is not a weakly prime, because it can be changed into another prime (641640091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320820000 + 320820001.

It is an arithmetic number, because the mean of its divisors is an integer number (320820001).

Almost surely, 2^641640001 is an apocalyptic number.

It is an amenable number.

641640001 is a deficient number, since it is larger than the sum of its proper divisors (1).

641640001 is an equidigital number, since it uses as much as digits as its factorization.

641640001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 641640001 is about 25330.6139088653. The cubic root of 641640001 is about 862.5093471227.

Adding to 641640001 its reverse (100046146), we get a palindrome (741686147).

The spelling of 641640001 in words is "six hundred forty-one million, six hundred forty thousand, one".