823641 has 24 divisors (see below), whose sum is σ = 1378944. Its totient is φ = 433440.

The previous prime is 823637. The next prime is 823643. The reversal of 823641 is 146328.

It is a happy number.

It is not a de Polignac number, because 823641 - 2² = 823637 is a prime.

823641 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (823643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1696 + ... + 2126.

It is an arithmetic number, because the mean of its divisors is an integer number (57456).

2⁸²³⁶⁴¹ is an apocalyptic number.

It is an amenable number.

823641 is a deficient number, since it is larger than the sum of its proper divisors (555303).

823641 is a wasteful number, since it uses less digits than its factorization.

823641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 461 (or 454 counting only the distinct ones).

The product of its digits is 1152, while the sum is 24.

The square root of 823641 is about 907.5466930136. The cubic root of 823641 is about 93.7373458476.

Adding to 823641 its reverse (146328), we get a palindrome (969969).

The spelling of 823641 in words is "eight hundred twenty-three thousand, six hundred forty-one".