10221821 has 8 divisors (see below), whose sum is σ = 10704960. Its totient is φ = 9741952.

The previous prime is 10221803. The next prime is 10221853. The reversal of 10221821 is 12812201.

It is a happy number.

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 10221821 - 2¹⁰ = 10220797 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 10221821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10221521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7490 + ... + 8748.

It is an arithmetic number, because the mean of its divisors is an integer number (1338120).

Almost surely, 2^10221821 is an apocalyptic number.

It is an amenable number.

10221821 is a deficient number, since it is larger than the sum of its proper divisors (483139).

10221821 is a wasteful number, since it uses less digits than its factorization.

10221821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1635.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 10221821 is about 3197.1582694637. The cubic root of 10221821 is about 217.0248295684.

The spelling of 10221821 in words is "ten million, two hundred twenty-one thousand, eight hundred twenty-one".