641761 has 2 divisors, whose sum is σ = 641762. Its totient is φ = 641760.

The previous prime is 641749. The next prime is 641789. The reversal of 641761 is 167146.

It is a happy number.

641761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 571536 + 70225 = 756^2 + 265^2 .

It is a cyclic number.

It is not a de Polignac number, because 641761 - 2⁷ = 641633 is a prime.

It is a super-2 number, since 2×641761² = 823714362242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (641701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320880 + 320881.

It is an arithmetic number, because the mean of its divisors is an integer number (320881).

2⁶⁴¹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

641761 is a deficient number, since it is larger than the sum of its proper divisors (1).

641761 is an equidigital number, since it uses as much as digits as its factorization.

641761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 25.

The square root of 641761 is about 801.0998689302. The cubic root of 641761 is about 86.2563560393.

The spelling of 641761 in words is "six hundred forty-one thousand, seven hundred sixty-one".