641110861 has 2 divisors, whose sum is σ = 641110862. Its totient is φ = 641110860.

The previous prime is 641110849. The next prime is 641110871. The reversal of 641110861 is 168011146.

641110861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 495908361 + 145202500 = 22269^2 + 12050^2 .

It is a cyclic number.

It is not a de Polignac number, because 641110861 - 2¹³ = 641102669 is a prime.

It is a super-2 number, since 2×641110861² = 822046272184322642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641110871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320555430 + 320555431.

It is an arithmetic number, because the mean of its divisors is an integer number (320555431).

Almost surely, 2^641110861 is an apocalyptic number.

It is an amenable number.

641110861 is a deficient number, since it is larger than the sum of its proper divisors (1).

641110861 is an equidigital number, since it uses as much as digits as its factorization.

641110861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 641110861 is about 25320.1670808073. The cubic root of 641110861 is about 862.2721872880.

The spelling of 641110861 in words is "six hundred forty-one million, one hundred ten thousand, eight hundred sixty-one".