10506821 has 4 divisors (see below), whose sum is σ = 11315052. Its totient is φ = 9698592.

The previous prime is 10506767. The next prime is 10506841. The reversal of 10506821 is 12860501.

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 7230721 + 3276100 = 2689^2 + 1810^2 .

It is a cyclic number.

It is not a de Polignac number, because 10506821 - 2⁶ = 10506757 is a prime.

It is a super-2 number, since 2×10506821² = 220786575052082, 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 (10506841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 404096 + ... + 404121.

It is an arithmetic number, because the mean of its divisors is an integer number (2828763).

Almost surely, 2^10506821 is an apocalyptic number.

It is an amenable number.

10506821 is a deficient number, since it is larger than the sum of its proper divisors (808231).

10506821 is an equidigital number, since it uses as much as digits as its factorization.

10506821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 808230.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 10506821 is about 3241.4226814780. The cubic root of 10506821 is about 219.0233637147.

The spelling of 10506821 in words is "ten million, five hundred six thousand, eight hundred twenty-one".