10055821 has 4 divisors (see below), whose sum is σ = 10075644. Its totient is φ = 10036000.

The previous prime is 10055819. The next prime is 10055827. The reversal of 10055821 is 12855001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4247721 + 5808100 = 2061^2 + 2410^2 .

It is a cyclic number.

It is not a de Polignac number, because 10055821 - 2¹ = 10055819 is a prime.

It is a super-2 number, since 2×10055821² = 202239071968082, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10055792 and 10055801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10055827) 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, 9130 + ... + 10171.

It is an arithmetic number, because the mean of its divisors is an integer number (2518911).

Almost surely, 2^10055821 is an apocalyptic number.

It is an amenable number.

10055821 is a deficient number, since it is larger than the sum of its proper divisors (19823).

10055821 is an equidigital number, since it uses as much as digits as its factorization.

10055821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19822.

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 10055821 is about 3171.0914524813. The cubic root of 10055821 is about 215.8436010612.

The spelling of 10055821 in words is "ten million, fifty-five thousand, eight hundred twenty-one".