811641 has 4 divisors (see below), whose sum is σ = 1082192. Its totient is φ = 541092.

The previous prime is 811637. The next prime is 811649. The reversal of 811641 is 146118.

811641 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 811641 - 2² = 811637 is a prime.

It is a super-2 number, since 2×811641² = 1317522225762, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

811641 is a lucky number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (811649) 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, 135271 + ... + 135276.

It is an arithmetic number, because the mean of its divisors is an integer number (270548).

2⁸¹¹⁶⁴¹ is an apocalyptic number.

It is an amenable number.

811641 is a deficient number, since it is larger than the sum of its proper divisors (270551).

811641 is a wasteful number, since it uses less digits than its factorization.

811641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270550.

The product of its digits is 192, while the sum is 21.

The square root of 811641 is about 900.9112053915. The cubic root of 811641 is about 93.2798829445.

Adding to 811641 its reverse (146118), we get a palindrome (957759).

The spelling of 811641 in words is "eight hundred eleven thousand, six hundred forty-one".