821621441 has 8 divisors (see below), whose sum is σ = 870204384. Its totient is φ = 773066560.

The previous prime is 821621357. The next prime is 821621447. The reversal of 821621441 is 144126128.

821621441 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 821621441 - 2¹⁰ = 821620417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821621447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100286 + ... + 108168.

It is an arithmetic number, because the mean of its divisors is an integer number (108775548).

Almost surely, 2^821621441 is an apocalyptic number.

It is an amenable number.

821621441 is a deficient number, since it is larger than the sum of its proper divisors (48582943).

821621441 is a wasteful number, since it uses less digits than its factorization.

821621441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14031.

The product of its digits is 3072, while the sum is 29.

The square root of 821621441 is about 28663.9397327025. The cubic root of 821621441 is about 936.6066881691.

Adding to 821621441 its reverse (144126128), we get a palindrome (965747569).

The spelling of 821621441 in words is "eight hundred twenty-one million, six hundred twenty-one thousand, four hundred forty-one".