11087821 has 4 divisors (see below), whose sum is σ = 11168892. Its totient is φ = 11006752.

The previous prime is 11087819. The next prime is 11087837. The reversal of 11087821 is 12878011.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12878011 = 97 ⋅132763.

It can be written as a sum of positive squares in 2 ways, for example, as 5470921 + 5616900 = 2339^2 + 2370^2 .

It is a cyclic number.

It is not a de Polignac number, because 11087821 - 2¹ = 11087819 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 11087821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11088821) 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, 40330 + ... + 40603.

It is an arithmetic number, because the mean of its divisors is an integer number (2792223).

Almost surely, 2^11087821 is an apocalyptic number.

It is an amenable number.

11087821 is a deficient number, since it is larger than the sum of its proper divisors (81071).

11087821 is an equidigital number, since it uses as much as digits as its factorization.

11087821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81070.

The product of its (nonzero) digits is 896, while the sum is 28.

The square root of 11087821 is about 3329.8379840467. The cubic root of 11087821 is about 222.9882959531.

It can be divided in two parts, 1108 and 7821, that multiplied together give a palindrome (8665668).

The spelling of 11087821 in words is "eleven million, eighty-seven thousand, eight hundred twenty-one".