891641 has 4 divisors (see below), whose sum is σ = 930432. Its totient is φ = 852852.

The previous prime is 891629. The next prime is 891643. The reversal of 891641 is 146198.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 891641 - 2⁶ = 891577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (891643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19361 + ... + 19406.

It is an arithmetic number, because the mean of its divisors is an integer number (232608).

2⁸⁹¹⁶⁴¹ is an apocalyptic number.

It is an amenable number.

891641 is a deficient number, since it is larger than the sum of its proper divisors (38791).

891641 is a wasteful number, since it uses less digits than its factorization.

891641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38790.

The product of its digits is 1728, while the sum is 29.

The square root of 891641 is about 944.2674409297. The cubic root of 891641 is about 96.2490998960.

The spelling of 891641 in words is "eight hundred ninety-one thousand, six hundred forty-one".