11057821 has 4 divisors (see below), whose sum is σ = 11209372. Its totient is φ = 10906272.

The previous prime is 11057777. The next prime is 11057843. The reversal of 11057821 is 12875011.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12875011 = 929 ⋅13859.

It can be written as a sum of positive squares in 2 ways, for example, as 3189796 + 7868025 = 1786^2 + 2805^2 .

It is a cyclic number.

It is not a de Polignac number, because 11057821 - 2¹³ = 11049629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11057861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75666 + ... + 75811.

It is an arithmetic number, because the mean of its divisors is an integer number (2802343).

Almost surely, 2^11057821 is an apocalyptic number.

It is an amenable number.

11057821 is a deficient number, since it is larger than the sum of its proper divisors (151551).

11057821 is an equidigital number, since it uses as much as digits as its factorization.

11057821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151550.

The product of its (nonzero) digits is 560, while the sum is 25.

The square root of 11057821 is about 3325.3302091672. The cubic root of 11057821 is about 222.7870032827.

The spelling of 11057821 in words is "eleven million, fifty-seven thousand, eight hundred twenty-one".