891601 has 2 divisors, whose sum is σ = 891602. Its totient is φ = 891600.

The previous prime is 891593. The next prime is 891617. The reversal of 891601 is 106198.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 641601 + 250000 = 801^2 + 500^2 .

It is a cyclic number.

It is not a de Polignac number, because 891601 - 2³ = 891593 is a prime.

It is not a weakly prime, because it can be changed into another prime (891661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445800 + 445801.

It is an arithmetic number, because the mean of its divisors is an integer number (445801).

2⁸⁹¹⁶⁰¹ is an apocalyptic number.

It is an amenable number.

891601 is a deficient number, since it is larger than the sum of its proper divisors (1).

891601 is an equidigital number, since it uses as much as digits as its factorization.

891601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 891601 is about 944.2462602521. The cubic root of 891601 is about 96.2476605942.

Adding to 891601 its reverse (106198), we get a palindrome (997799).

The spelling of 891601 in words is "eight hundred ninety-one thousand, six hundred one".