10566821 has 4 divisors (see below), whose sum is σ = 11026272. Its totient is φ = 10107372.

The previous prime is 10566799. The next prime is 10566833. The reversal of 10566821 is 12866501.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12866501 = 17 ⋅756853.

It is a cyclic number.

It is not a de Polignac number, because 10566821 - 2⁶ = 10566757 is a prime.

It is a super-2 number, since 2×10566821² = 223315412092082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10566851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 229691 + ... + 229736.

It is an arithmetic number, because the mean of its divisors is an integer number (2756568).

Almost surely, 2^10566821 is an apocalyptic number.

It is an amenable number.

10566821 is a deficient number, since it is larger than the sum of its proper divisors (459451).

10566821 is an equidigital number, since it uses as much as digits as its factorization.

10566821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459450.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 10566821 is about 3250.6647012573. The cubic root of 10566821 is about 219.4394891342.

The spelling of 10566821 in words is "ten million, five hundred sixty-six thousand, eight hundred twenty-one".