641289161 has 4 divisors (see below), whose sum is σ = 641594772. Its totient is φ = 640983552.

The previous prime is 641289127. The next prime is 641289169. The reversal of 641289161 is 161982146.

641289161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 210975625 + 430313536 = 14525^2 + 20744^2 .

It is a cyclic number.

It is not a de Polignac number, because 641289161 - 2¹⁴ = 641272777 is a prime.

It is a super-2 number, since 2×641289161² = 822503576032167842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641289169) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 149636 + ... + 153861.

It is an arithmetic number, because the mean of its divisors is an integer number (160398693).

Almost surely, 2^641289161 is an apocalyptic number.

It is an amenable number.

641289161 is a deficient number, since it is larger than the sum of its proper divisors (305611).

641289161 is a wasteful number, since it uses less digits than its factorization.

641289161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305610.

The product of its digits is 20736, while the sum is 38.

The square root of 641289161 is about 25323.6877448763. The cubic root of 641289161 is about 862.3521156800.

The spelling of 641289161 in words is "six hundred forty-one million, two hundred eighty-nine thousand, one hundred sixty-one".